Faucet 'P' can fill the tank completely in12 hrs while faucet'q' can empty it by 24 hrs. By mistake, Anitha forgot to close the faucet ‘q’, As a result, both the faucet remained open. After 8 hrs, faucet realized the mistake and immediately closed the faucet 'q'. In how much time now onwards, would the tank be full? A) 4 B) 8 C) 12 D) 16

Faucet 'P' can fill the tank completely in12 hrs while faucet'q' can empty it by 24 hrs. By mistake, Anitha forgot to close the faucet ‘q’, As a result, both the faucet remained open. After 8 hrs, faucet realized the mistake and immediately closed the faucet 'q'. In how much time now onwards, would the tank be full? A) 4 B) 8 C) 12 D) 16 
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1 Answer

Answer :

Answer: B

Explanation:

Faucet P can fill the tank completely in 12 hours

=> In 1 hour, Faucet P can fill 1/12of the tank

Faucet q can empty the tank completely in 24 hours

=> In 1 hour, Faucet q can empty 1/24 of the tank

i.e., In one hour, Tank p and q together can effectively fill (1/12-1/24)=1/24of the tank

=> In 8 hours, Tank p and q can effectively fill 1/24×8=1/3 of the tank.

Time taken to fill the remaining (1−1/3)=2/3of the tank =(2/3)/(1/12) = 8 hours
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Related questions

A boat covers 12 km upstream and 18km downstream in 3hrs while it covers 18 km upstream and 12km downstream in 3 ¼ hrs the velocity of the the boat upstream and downstream? A) 4,8 B) 8,12 C) 12,16 D) 3,9

Description : A boat covers 12 km upstream and 18km downstream in 3hrs while it covers 18 km upstream and 12km downstream in 3 ¼ hrs the velocity of the the boat upstream and downstream? A) 4,8 B) 8,12 C) 12,16 D) 3,9 

Last Answer : ANSWER : B 

A boat takes 38 hrs for travelling downstream from point p to point q and coming back to a point r midway between p and q. If the velocity of the stream is 8 km/hr and the speed of the boat in still water is 28 km/hr. What is the distance between p and q? A) 720 B) 640 C) 510 D) 450

Description : A boat takes 38 hrs for travelling downstream from point p to point q and coming back to a point r midway between p and q. If the velocity of the stream is 8 km/hr and the speed of the boat in still water is 28 km/hr. What is the distance between p and q? A) 720 B) 640 C) 510 D) 450

Last Answer : ANSWER: A Explanation: Speed downstream = (28 + 8)km/hr = 36 km/hr Speed upstream = (28 – 8)km/hr = 20 km/hr Let the distance between p and q be ‘x’km Then, x/36 + (x/2)/20 = 38 x/36 +x/40 = 38 19x = 13680 X = 720 km Therefore the distance between p and q is 720km

A motorboat running upstream takes 4 hrs 24 mins to cover a certain distance, while it takes 2hrs to cover the same distance running downstream. What is the ratio between the speed of the boat and speed of the water current respectively? A) 8:3 B) 5:2 C) 3:7 D) 2:4

Description : A motorboat running upstream takes 4 hrs 24 mins to cover a certain distance, while it takes 2hrs to cover the same distance running downstream. What is the ratio between the speed of the boat and speed of the water current respectively? A) 8:3 B) 5:2 C) 3:7 D) 2:4

Last Answer : ANSWER : A Explanation: Let the man's rate upstream be x'km/hr and downstream be y'km/hr Then distance covered upstream by 4hrs 24mints = distance covered by downstream in 2hrs (x * 4 2/5) = y *2 22x/5 = 2y Y = ... = (y+x/2) : (y -x/2) = 16x/10 : 6x/10 = 16x : 6x = 8:3

A boys rows to a certain place and comes back, but by mistake he covers 2/3rd more distance while coming back. The total time for this journey is 20 hours. The ratio of speed of boat to that of stream is 2 : 1. If the difference between upstream and downstream speed is 24km/hr, then how much time will the man take to reach to starting point from his present position? A) 2hr 13mints B)1hr 30 mins C) 2hr 30mins D)1hr 40 mins

Description : A boys rows to a certain place and comes back, but by mistake he covers 2/3rd more distance while coming back. The total time for this journey is 20 hours. The ratio of speed of boat to that of ... starting point from his present position? A) 2hr 13mints B)1hr 30 mins C) 2hr 30mins D)1hr 40 mins

Last Answer : ANSWER : A Explanation: let speed of boat and stream be 2x and x respectively So downstream speed = 2x+x = 3x, and upstream speed = 2x-x = x Let total distance between points is d km So he covered d ... with speed 3x = 48 km/hr(downstream) So time is 80/36 * 60 = 133.33 minutes = 2hr 13mins

Mohana can row 80km upstream and 110km downstream in 26 hrs. Also she can 60km upstream and 88km downstream in 20 hrs. Find the speed of the girl in still water and the speed of the current in ratio: A) 5:6 B) 3:6 C) 7:9 D) 8:3

Description : Mohana can row 80km upstream and 110km downstream in 26 hrs. Also she can 60km upstream and 88km downstream in 20 hrs. Find the speed of the girl in still water and the speed of the current in ratio: A) 5:6 B) 3:6 C) 7:9 D) 8:3 

Last Answer : ANSWER : D Explanation: Let rate upstream = x' km/hr and  Rate downstream = y' km/hr  Then 80/x + 110/y = 26 ---1  60/x + 88/y = 20--2  By solving 1 and 2  y= 11 ; x = 5  Rain in still water ... 5) km/hr = 8 km/hr  Rain of current = ½ (11 - 50) km/hr = 3 km/hr  The required answer is 8:3

A boat takes 24 hours to cover 128 km downstream and 16 hours to cover 64 km upstream. Then the speed of the boat in still water is: A) 14/3 B) 8/7 C) 3/2 D) 9/5

Description : A boat takes 24 hours to cover 128 km downstream and 16 hours to cover 64 km upstream. Then the speed of the boat in still water is: A) 14/3 B) 8/7 C) 3/2 D) 9/5

Last Answer : Answer: A Explanation: Distance covered in downstream = 128km Time taken in downstream = 24 hours. Rate of downstream = distance / time = a = 128 km /24 hours = 16/3km/hr Distance covered in upstream = 64km Time taken in upstream ... / 2 = (1/2)(16/3+4) km/hr = (1/2)(28/3)km/hr = 14/3km/hr.

A woman rows to a place 24km distant and come back in 7 hrs. She finds that she can row 2km with the stream in the same time as 1.5km against the stream. The rate of the stream is, A) 2 B) 4 C) 1 D) 3

Description : A woman rows to a place 24km distant and come back in 7 hrs. She finds that she can row 2km with the stream in the same time as 1.5km against the stream. The rate of the stream is, A) 2 B) 4 C) 1 D) 3

Last Answer : ANSWER: C  Explanation:  Suppose she move 2km downstream in x hrs  Then, speed of downstream = (2/x) km/hr  Speed of upstream = (1.5/x) km/hr  Therefore 24/(2/x) + 24/(1.5/x) = 7  12x + 16x = 7 ... of downstream = 8km/hr and upstream = 6km/hr  Rate of the stream = ½ (8 - 6 )km/hr  = 1 km/hr

A boat man lakes 5hrs 30 mins to row a boat 30km downstream of a river and 4 hrs 15mints to cover a distance of 10km upstream. Find the speed of the river current in km/hr. A) 1.5 km/hr B) 3km/hr C) 5km/hr D) 7 km/hr

Description : A boat man lakes 5hrs 30 mins to row a boat 30km downstream of a river and 4 hrs 15mints to cover a distance of 10km upstream. Find the speed of the river current in km/hr. A) 1.5 km/hr B) 3km/hr C) 5km/hr D) 7 km/hr

Last Answer : ANSWER: A  Explanation:  Rate downstream = (30 / 5 ½ ) km/hr  = 30 / (11/2) km/hr  = 30 * 2 / 11 km/hr = 60/11 km/hr  Rate upstream = (10 / 4 ¼)km/hr  = 10 / (17/4)km/hr  = 10 * 4 / 17 km/hr = ...  Speed of current = 1 / 2 (a - b) km/hr  =1 / 2 (60 / 11 - 40 / 17)  = 1.5 km/hr (approx.)

A pedal boat goes 12km upstream and 14km downstream in 3hrs. It goes 15km upstream and 10.5km downstream in 3 hrs 15mints. The speed of the boat in still water is A) 10 B) 15 C) 20 D) 25

Description : A pedal boat goes 12km upstream and 14km downstream in 3hrs. It goes 15km upstream and 10.5km downstream in 3 hrs 15mints. The speed of the boat in still water is A) 10 B) 15 C) 20 D) 25 

Last Answer : ANSWER: A

A boat takes 27 hrs to travel a distance upstream and takes 9hrs to travel the same distance downstream. If the speed of the boat in still water is 12km/hr, then what is the velocity of the stream? A) 8km/hr B) 6km/hr C) 4km/hr D) None of these

Description : A boat takes 27 hrs to travel a distance upstream and takes 9hrs to travel the same distance downstream. If the speed of the boat in still water is 12km/hr, then what is the velocity of the stream? A) 8km/hr B) 6km/hr C) 4km/hr D) None of these

Last Answer : ANSWER : B  Explanation: Let the velocity of the stream be ‘ y’ km/hr Then the speed of the downstream = (12 + y)km/hr The speed of the upstream = (12 – y)km/hr 9 (12 + y) = 27 (12 – y) 108 + 9y = 324 – 27y 27y + 9y = 324 - 108 36y = 216 y = 6 km/hr

There is a bridge besides a river. Two friends Arun and varun started their journey from place L, moved to the garden located at another place M & then returned to place L. Arun moves by swimming at a speed of 30 km/hr while Varun sails on a boat at a speed of about 24km/hr. If the flow of water current is at the speed of 12km/hr, what will be the average speed of boat sailor? A) 36 B) 18 C) 24 D) 48

Description : There is a bridge besides a river. Two friends Arun and varun started their journey from place L, moved to the garden located at another place M & then returned to place L. Arun moves by swimming at a speed of 30 ... 12km/hr, what will be the average speed of boat sailor? A) 36 B) 18 C) 24 D) 48 

Last Answer : ANSWER:B Explanation: As Arun swims both the ways at the speed of 30km/hr, the average speed of swimming is 30 km/hr Being a boat sailor, varun moves downstream at speed =24 +12=36km/hr and upstream at speed = 24-12= ... Upstream Speed])] = (36*12)/0.5(36+12) km/hr = 432/24 km/hr = 18 km/hr

Thanu can travel 24 miles downstream in a certain river in 12hrs less than it takes him to travel the same distance upstream. But if he could double his usual rowing rate for his 48 mile round trip, the downstream 24 miles would then take only 2hr less than the upstream 24miles. What is the speed of the current in miles per hour? A) 2 / 3 miles/hr B) 8 / 3 miles/hr C) 7 / 5 miles/hr D) 3 / 5 miles/hr

Description : Thanu can travel 24 miles downstream in a certain river in 12hrs less than it takes him to travel the same distance upstream. But if he could double his usual rowing rate for his 48 mile round trip, the downstream 24 miles would ... 3 miles/hr B) 8 / 3 miles/hr C) 7 / 5 miles/hr D) 3 / 5 miles/hr 

Last Answer : ANSWER : B 

If a boy rows 8 km downstream in 6 hours and 4 km upstream in 4 hours then how long will he take to cover 16 km in stationary (still) water? A) 8 B) 14 C) 22 D) 16

Description : If a boy rows 8 km downstream in 6 hours and 4 km upstream in 4 hours then how long will he take to cover 16 km in stationary (still) water? A) 8 B) 14 C) 22 D) 16 

Last Answer : Answer: B Explanation: Distance covered in downstream = 8 km Time taken in downstream = 6 hours. Rate of downstream = 8/6=4/3 km/hr Distance covered in upstream = 4 km Time taken in upstream = 4hours. ... 3+1) = 7/6km/hr Time Taken to cover 16 km in still water = 16*6/7=14hrs (approximately)

Two pipe P & Q fill a tab in 5 hrs and 20 hrs respectively. If both the pipes are open then due to the leakage, it took 30mins more to fill the tab. If the tab is full, how long will it take for the leakage alone to empty the tank? A) 28 B) 24 C) 36 D) 12

Description : Two pipe P & Q fill a tab in 5 hrs and 20 hrs respectively. If both the pipes are open then due to the leakage, it took 30mins more to fill the tab. If the tab is full, how long will it take for the leakage alone to empty the tank? A) 28 B) 24 C) 36 D) 12

Last Answer : C Part filled by(P+Q) in 1 hr = 1/5 + 1/20 = ¼ So P & Q together can fill the tank in 4 hrs. Work done by the leak in 1 hr = 1 / 4 - 2/9 Leak will empty the tank in 36 hrs.

A motorboat can cover 80 km upstream and 120 km downstream together in 26 hours. Also it can cover 100 km upstream and 144 km downstream together in 32 hours. What is the speed of the motorboat in still water? A) 12 km/hr B) 15km/hr C) 8.5km/hr D) 19km/hr

Description : A motorboat can cover 80 km upstream and 120 km downstream together in 26 hours. Also it can cover 100 km upstream and 144 km downstream together in 32 hours. What is the speed of the motorboat in still water? A) 12 km/hr B) 15km/hr C) 8.5km/hr D) 19km/hr 

Last Answer : ANSWER :C Explanation:  Upstream speed in both cases is 80 and 100.  Ratio is 80 : 100 = 8:10 = 4 : 5.  So let times in both cases be 4x and 5x  Downstream speed in both cases is 120 and 144 resp.  Ratio is ... 12 km/hr  So speed of boat = 1/2 * (5+12) =17/2km/hr  speed of boat = 8.5 km/hr

A mototboat can row to a place 112 km away and come back in 44 hours. The time to row 42 km with the stream is same as the time to row 24 km against the stream. Find the speed of boat in still water. A) 5.5 km/hr B) 7.5km/hr C) 10.5 km/hr D) 3.5 km/hr

Description : A mototboat can row to a place 112 km away and come back in 44 hours. The time to row 42 km with the stream is same as the time to row 24 km against the stream. Find the speed of boat in still water. A) 5.5 km/hr B) 7.5km/hr C) 10.5 km/hr D) 3.5 km/hr 

Last Answer : ANSWER: A Explanation: Downstream speed = 42/x km/hr Upstream speed = 24/x km/hr 112 / (42 / x) + 112 / (24 / x) = 44 112[x /42 + x / 24] = 44 112 / 3 [x / 14 + x / 8] = 44 11x / 56 = 44 * ... = 4 km/hr Speed of boat = 1/2 * (7 + 4) km/hr = 11 /2 speed of boat in still water = 5.5 km/hr

A boat goes 3.5km upstream in 24 mins and the speed of the stream is 1.5km per hour, then the speed of the boat in still water is. A) 4.3 km/hr B) 7.4 km/hr C) 5.2km/hr D) 10.25km/hr

Description : A boat goes 3.5km upstream in 24 mins and the speed of the stream is 1.5km per hour, then the speed of the boat in still water is. A) 4.3 km/hr B) 7.4 km/hr C) 5.2km/hr D) 10.25km/hr

Last Answer : ANSWER: D  Explanation:  Speed of upstream = 3.5 / 24 km/min  = 3.5 / 24 * 60 km/hr = 8.75 km/hr  Speed of the stream = ½ (a - b)km/hr = 1.5 km/hr  1.5 = ½ ( a- 8.75)km/hr  a = 11.75 km/hr ... (a + b) km/hr  = ½ (11.75 + 8.75) = ½(20.5)  The speed of the boat in still water = 10.25 km/hr

A girl can row 15 kmph in still water and he finds that it takes him thrice as long to row up as to row down the river. Find the rate of stream. A) 2.5 B) 5.5 C) 7.5 D) 12.5

Description : A girl can row 15 kmph in still water and he finds that it takes him thrice as long to row up as to row down the river. Find the rate of stream. A) 2.5 B) 5.5 C) 7.5 D) 12.5 

Last Answer : Answer: C Explanation: Given that, time taken to travel upstream = 3 time taken to travel downstream When distance is constant, speed is inversely proportional to the time Hence, 3 speed upstream = speed downstream ... ., speed upstream =7. 5 km/hr Rate of stream =1/2(3x−x)= x = 7.5km/hr

X, Y , Z are three towns on a lake which flows uniformly. Y is equidistant from X and Z. A man rows from X to Y and returns in 20hrs. He can row from X to Z in 8 hr. The ratio of speed of the man in still water to the speed of the current is. A) 3:5 B) 5:3 C) 2:3 D) None of these

Description : X, Y , Z are three towns on a lake which flows uniformly. Y is equidistant from X and Z. A man rows from X to Y and returns in 20hrs. He can row from X to Z in 8 hr. The ratio of speed of the man in still water to the speed of the current is. A) 3:5 B) 5:3 C) 2:3 D) None of these

Last Answer : ANSWER: A Explanation: Let the speed of man in still water = x km/hr Speed of the current = y km/hr Speed of downstream = (x+ y) km/hr Speed of upstream = ( x - y) km/hr Let the lake be flowing from X to Z and  xy = yz a ... y = 1 / 4  4x - 4y = x + y  3x = 5y x / y = 3 / 5 x : y = 3 : 5

A pedal boat can cover 20km in 1 hr in still water. And it takes thrice as much as time to cover up than as to cover down the same distance in running water. The speed of the current is. A) 7.5 km/hr B) 20 km/hr C) 5 km/hr D) 10 km/hr

Description : A pedal boat can cover 20km in 1 hr in still water. And it takes thrice as much as time to cover up than as to cover down the same distance in running water. The speed of the current is. A) 7.5 km/hr B) 20 km/hr C) 5 km/hr D) 10 km/hr

Last Answer : ANSWER : D Explanation: Let the speed of upstream be x' km/hr Then speed in downstream = 3x km/hr[thrice as much as time to cover up than as to cover down the same distance in running water] Speed in ...  Speed in downstream = 30 km/hr  Hence speed of the current = (30 -10)/2  = 10 km/hr.

A fisherman rows to a place 24km distance and back in 7 hours. He finds that he can row 2km with the stream in the same time 1.5 km against the stream.The rate of the stream is? A) 7 B) 5 C) 3 D) 1

Description : A fisherman rows to a place 24km distance and back in 7 hours. He finds that he can row 2km with the stream in the same time 1.5 km against the stream.The rate of the stream is? A) 7 B) 5 C) 3 D) 1 

Last Answer : Answer: D  Explanation: Let be moves 2 km downstream in x Hours Then in speed downstream = 2/x kmph Speed in upstream = 1.5/x kmph ==> 24/2/X + 24/1.5/X = 7 12x+16x=7 Therefore x=1/4 Speed in downstream = 8 Kmph Speed in upstream = 6 Kmph Then the Rate of stream = 1/2 (8 - 6) = 1 Kmph

A boatman can take the same time to row6.5km downstream and 3.5km upstream. His speed in still water 2.5 km/hr. The speed of the stream is. A) 0.75 km/hr B) 2.5 km/hr C) 1.5km/hr D) 7.5km/hr

Description : A boatman can take the same time to row6.5km downstream and 3.5km upstream. His speed in still water 2.5 km/hr. The speed of the stream is. A) 0.75 km/hr B) 2.5 km/hr C) 1.5km/hr D) 7.5km/hr

Last Answer : ANSWER: A Explanation: Given that the speed in still water = 2.5 km/hr Let the speed of the stream be x; km/hr speed in upstream = (2.5 - x)km/hr Then time taken to cover 6.5 km downstream = 6.5 / (2.5+x) ... 5x = 8.75 + 3.5x 10 x = 7.5 x = 0.75 km/hr The speed of the stream is 0.75 km/hr

There are 3 poles M, N and O in a straight line such that point N is equidistant from points M and O. A boat can travel from point M to O downstream in 6 hours and from N to M upstream in 4 hours. Find the ratio of boat in still water to speed of stream. A) 2:3 B) 7:1 C) 3:2 D) 1:7

Description : There are 3 poles M, N and O in a straight line such that point N is equidistant from points M and O. A boat can travel from point M to O downstream in 6 hours and from N to M upstream in 4 hours. Find the ratio of boat in still water to speed of stream. A) 2:3 B) 7:1 C) 3:2 D) 1:7

Last Answer : ANSWER: B Explanation: Let speed in still water = x km/hr, of current = y km/hr Downstream speed = (x+y) km/hr Upstream speed = (x - y) km/hr Let MO = 2p km. So MN = NO = p km.  So 2p/(x+y) = 6 --------1  p/ ... - 2y) = 6x + 6y  8x - 8y = 6x +6y  2x = 14y  x/y = 14 / 2 = 7/1  x : y = 7 :1

Dhanvanth can swim at 15 km/hr in stagnant water. In a river with 3 km/hr current, he swims to a certain distance and comes back within 100 min. What is the distance between the two points? A) 11km B) 13km C) 19km D) 12km

Description : Dhanvanth can swim at 15 km/hr in stagnant water. In a river with 3 km/hr current, he swims to a certain distance and comes back within 100 min. What is the distance between the two points? A) 11km B) 13km C) 19km D) 12km

Last Answer : ANSWER: D Explanation: Speed in still water (a) = 15 km/hr Speed in current( b) = 3 km/hr Upstream speed = a - b = 15 - 3 = 12 km/hr Downstream speed = a + b = 15 + 3 = 18 km/hr Let the ... 36 = 5 / 3 15x = 36 * 5 x = 36 * 5 / 15 = 12 km Distance between the two points is 12km

A man goes 4km upstream of the stream in 2hr and goes 2km downstream of the stream in 20mints. How long will it take to go 10km in stationary water? A) 1hr 15mits B) 2hrs 30mints C) 5hrs 30mints D) 3hrs 45mints

Description : A man goes 4km upstream of the stream in 2hr and goes 2km downstream of the stream in 20mints. How long will it take to go 10km in stationary water? A) 1hr 15mits B) 2hrs 30mints C) 5hrs 30mints D) 3hrs 45mints

Last Answer : ANSWER : B Explanation:  Rate downstream = (2/20 * 60) km/hr  = 6 km/hr  Rate upstream = 2 km/hr  Speed in still water = ½(6+2)km/hr  = 4 km/hr  Required time = distance / speed  = (10/4) hrs =(5/2)hrs =2 ½ hrs = 2hrs 30mits.

A motor boat sails 30 km of a river towards upstream in 10hrs. How long will it take to cover the same distance downstream, if the speed of the current is ½ of the speed of the boat in still water. A) 1.8hrs B) 3.33hrs C) 5hrs D) None of these

Description : A motor boat sails 30 km of a river towards upstream in 10hrs. How long will it take to cover the same distance downstream, if the speed of the current is ½ of the speed of the boat in still water. A) 1.8hrs B) 3.33hrs C) 5hrs D) None of these

Last Answer : ANSWER : B  Explanation:  Upstream speed = x –y  Downstream speed = x + y  x– y = 30/10 = 3km/hr  Again x = 2y  Therefore x – y = 3  y= 3km/hr ; x = 6km/hr  Therefore x + y = 9 km/hr  Time during downstream = 30/9 = 3.33hrs

Sakthi rows a boat at 4 km upstream in 1hour and 1 km downstream in 20 minutes. How long will he take to reach 3.5km in still water? A) 1 B) 2 C) 3 D) 4

Description :  Sakthi rows a boat at 4 km upstream in 1hour and 1 km downstream in 20 minutes. How long will he take to reach 3.5km in still water? A) 1 B) 2 C) 3 D) 4

Last Answer : ANSWER:A Explanation: Upstream Speed = 4/1 = 4km/hr Downstream Speed = 1/20 = 0.05 km/min = 0.05*60 = 3 km/hr Hence, speed of boat = 1/2( Upstream Speed + Downstream Speed) = 1/2 (4+3 ... , the time required to reach the distance of 3.5 km=DistanceCovered/Speed of boat = 3.5/3.5km/hr =1 km/hr

A man can row 4 km against the stream in 40mins and return in 36mins. Find the rate of current. A) 1/2 km/hr B) 1/3 km/hr C) 2/3 km/hr D) 1/4 km/hr

Description : A man can row 4 km against the stream in 40mins and return in 36mins. Find the rate of current.  A) 1/2 km/hr B) 1/3 km/hr C) 2/3 km/hr D) 1/4 km/hr

Last Answer : ANSWER: B  Explanation:  Speed of the man (upstream) = (4 / 40 * 60) km/hr  = 6 km/hr  Speed of the man (downstream) = ( 4 / 36 * 60) km/hr  = (60 / 9)km/hr  = 20/3 km/h  Rate of the current = ½[downstream ... 6] km/hr  = ½ [ 20 - 18/3] km/hr  = ½ [2/3]km/hr Rate of the current = 1/3 km/hr

A boy rows 1500m in 1350 seconds against the stream and returns in 15 minutes. His rowing speed in still water is. A) 5km/hr B) 4km/hr C) 7km/hr D) 9km/hr

Description : A boy rows 1500m in 1350 seconds against the stream and returns in 15 minutes. His rowing speed in still water is. A) 5km/hr B) 4km/hr C) 7km/hr D) 9km/hr

Last Answer : ANSWER : A  Explanation:  Rate upstream = (1500 / 1350) m/s = (150/135) m/s = 10/9 m/s  Rate downstream = (1500 / 900)m/s = (15/9)m/s  = 5/3 m/s  Rate in still water = ½ [ a+ b]  = ½[10 / 9 + 5 /3 ... +15 / 9]  = ½[25/9]  = 25/18 m/s  = (25/18) * (18/5)km/hr  speed in still water = 5km/hr

At the same speed a boat travelling 50km upstream and 78km downstream in 16hrs. Also it can travel 70km upstream and 104km downstream, in 22hrs at the same speed of the stream is. A) 5km/hr B) 3km/hr C) 4km/hr D) 2km/hr

Description : At the same speed a boat travelling 50km upstream and 78km downstream in 16hrs. Also it can travel 70km upstream and 104km downstream, in 22hrs at the same speed of the stream is. A) 5km/hr B) 3km/hr C) 4km/hr D) 2km/hr

Last Answer : ANSWER : C

3 faucet P,Q & R can fill a cistern in 12 hrs. After working together for 4hrs, R is closed P and Q can fill the remaining part in 14 hrs. The number of hrs taken by R alone to fill the cistern is. A) 18 hrs B) 20 hrs C) 28hrs D) 30hrs

Description :  3 faucet P,Q & R can fill a cistern in 12 hrs. After working together for 4hrs, R is closed P and Q can fill the remaining part in 14 hrs. The number of hrs taken by R alone to fill the cistern is. A) 18 hrs B) 20 hrs C) 28hrs D) 30hrs

Last Answer : C  Part filled in 4 hrs = 4/12 = 1/3 Remaining part = 2/3 (P+Q)’s 14 hrs work = 2/3 (P+Q)’s 1 hr work = 2/ 3 *14 = 1/21 R’s 1 hr work = (P+Q+R)’s 1 hr work – (P+Q)’s 1 hr work = 1/12 – 1/21 = 7-4/84 = 3/84 = 1/28 R alone can fill the tank in 28 hrs.

Faucet A and B can fill a tank in 15 and 9 hrs respectively. Faucet C can empty it in 45 h. The tank is half full. All the three faucets are in operation simultaneously. After how much time the tank will be full ? A) 1(7/15)hrs B) 2(1/11)hrs C) 3(3/14)hrs D) 3(3/11)hrs

Description : Faucet A and B can fill a tank in 15 and 9 hrs respectively. Faucet C can empty it in 45 h. The tank is half full. All the three faucets are in operation simultaneously. After how much time the tank will be full ? A) 1(7/15)hrs B) 2(1/11)hrs C) 3(3/14)hrs D) 3(3/11)hrs

Last Answer : C In 1 hr = 1/15+1/9 – 1/45 =>3+5-1/45 = 7/45 ½ tank filled by 3 Faucets = 45/7*1/2 => 45/14 =>3(3/14)

Two faucet P and Q can fill a tank in 10 min. and 20 min. respectively. A water faucet R can empty the tank in 10 min. First P and Q are opened. After 3 min, R is also opened. In how much time, the tank is full? A) 17m B) 15m C) 11m D) 19m

Description : Two faucet P and Q can fill a tank in 10 min. and 20 min. respectively. A water faucet R can empty the tank in 10 min. First P and Q are opened. After 3 min, R is also opened. In how much time, the tank is full? A) 17m B) 15m C) 11m D) 19m

Last Answer :  C Part filled in 3 min. = 3*((1/10)+(1/20)) = 3 * (2+1/20) =>3(3/20) = 9/20 Remaining part=(1-(9/20))=(11/20). Net part filled in 1min. when P,Q and R are opened=(1/10)+(1/ ... (1/20). Now,(1/20) part is filled in one minute. (11/20) part is filled in = (20*(11/20))=11minutes.

Two faucet p and q can fill a tank in 10 minutes and 20 minutes.If both faucet are opened simultaneously , after how much time should q be closed so that the tank is full in 9 minutes ? A) 2 min B) 9 min C) 4 min D) 7min

Description : Two faucet p and q can fill a tank in 10 minutes and 20 minutes.If both faucet are opened simultaneously , after how much time should q be closed so that the tank is full in 9 minutes ? A) 2 min B) 9 min C) 4 min D) 7min

Last Answer : A p fill the tank in 1 minute (10×2 = 20) = 2 units q fill the tank in 1 minute (20×1 = 20) = 1units For 9 min(p) = 9×2 = 18 units Remaining = 20 – 18 = 2 units Time for q be closed so that the tank is full in 9 minutes = 2/1 = 2 min

Two pumps P & Q can fill a tank in 12 mins and 15 mins respectively while a third pipe R can empty the full tank in 6 mins. P & Q kept open for 5 mins in the beginning and then R is also opened. In what time is tank emptied? A) 30mins B) 35mins C) 40mins D) 45 mins

Description : Two pumps P & Q can fill a tank in 12 mins and 15 mins respectively while a third pipe R can empty the full tank in 6 mins. P & Q kept open for 5 mins in the beginning and then R is also opened. In what time is tank emptied? A) 30mins B) 35mins C) 40mins D) 45 mins

Last Answer : D Part filled in 5 min = 5(1/12 +1/15) = 5*9/60 = ¾ Part emptied in 1 min when all the pumps are opened, = 1/6 – (1/12 + 1/15) = 1/6 – 3/20 = 1/60 Now 1/60 is part emptied in 1 min Therefore ¾ part will be emptied in 60 * ¾ = 45 mins

24 pumps are connected to a tank. Some of them are inlet pumps and the others are outlet pumps. Each of the inlet pumps an fill the tank in 16hours and each of the outlet pumps can empty the tank completely in 12hours. If all the pumps are kept open, the empty tank gets filled in 48 hours. How many inlet pumps are there? A) 16 B) 18 C) 17 D) 14

Description : 24 pumps are connected to a tank. Some of them are inlet pumps and the others are outlet pumps. Each of the inlet pumps an fill the tank in 16hours and each of the outlet pumps can empty the tank completely in ... gets filled in 48 hours. How many inlet pumps are there? A) 16 B) 18 C) 17 D) 14

Last Answer : D (x/16)-[(24-x)/12] = 1/48 x/16-24/48+x/12=1/48 (3+4)x/48=97/48 7x/48=97/48 7x=97 X=14

Two faucet can fill a tank in 12hours and 16 hours .While a third faucet empties the full tank in 24 hours.If all the three faucet are operate simultaneously, In how much time will the tank be filled ? A) 4 hours 12mins B) 4hours 48min C) 9hours 36mins D) 5hours 48min

Description : Two faucet can fill a tank in 12hours and 16 hours .While a third faucet empties the full tank in 24 hours.If all the three faucet are operate simultaneously, In how much time will the tank be filled ? A) 4 hours 12mins B) 4hours 48min C) 9hours 36mins D) 5hours 48min

Last Answer : C  1/12+1/16 – 1/24 = (4+3-2)/48  =>5/48  Time taken to fill the tank = 48/5 = 9hours 36min

Taps P, Q and R can fill a tank in 3, 4 and 5 hours respectively. If all the taps are opened together and after 30 minutes taps Q and R are turned off, find the total time in which the tank is full. A) 2(3/8)hrs B) 1(1/7)hrs C) 2(13/40)hrs D) 3(13/43)hrs

Description : Taps P, Q and R can fill a tank in 3, 4 and 5 hours respectively. If all the taps are opened together and after 30 minutes taps Q and R are turned off, find the total time in which the tank is full. A) 2(3/8)hrs B) 1(1/7)hrs C) 2(13/40)hrs D) 3(13/43)hrs

Last Answer : C In 1 hr P, Q, R = 1/3+1/4+1/5 = 20+15+12/60 = 47/60 Filled in 30m = 47/120 Remaining = 1-47/120 =73/120 Tap P = 3*73/120= 219/120 Total = 219/120+1/2 =219+60 /120= 279/120= 2 13/40 hrs

Pipes P, Q and R which fill the tank together in 12 hours are opened for 2hours after which pipe R was closed. Find the number of hours taken by pipe R to fill the tank if the remaining tank is filled in 14 hours. A) 16 B) 14 C) 20 D) 42

Description : Pipes P, Q and R which fill the tank together in 12 hours are opened for 2hours after which pipe R was closed. Find the number of hours taken by pipe R to fill the tank if the remaining tank is filled in 14 hours. A) 16 B) 14 C) 20 D) 42

Last Answer : D 1/P + 1/Q + 1/R = 1/12 Now given that first all open for 2hours, then R closed and P+Q completes in 14 hours, so (1/P + 1/Q + 1/R) *2 + (1/P + 1/Q)*14 = 1 Put 1/P + 1/Q = 1/12 – 1/R (1/12 – 1/R + 1/R) *2 + (1/12 – 1/R)*14 = 1 1/6+ 14/12 – 14/R = 1 Solve, R = 42

Pipe A can fill a water tank in 8 hours, Pipe B can fill the same tank in 12 hours and Pipe C can empty the tank in 24 hours. If all three pipes are opened together, in how many hours will the tank be completely filled or empty? a) 4.8 hours b) 5 hours c) 5.4 hours d) 6 hours e) 7.2 hours

Description : Pipe A can fill a water tank in 8 hours, Pipe B can fill the same tank in 12 hours and Pipe C can empty the tank in 24 hours. If all three pipes are opened together, in how many hours will the tank be completely filled or empty? a) 4.8 hours b) 5 hours c) 5.4 hours d) 6 hours e) 7.2 hours

Last Answer : If all the three pipes are opened together, in one hour they will fill 1/8 + 1/12 – 1/24 = (3+2-1)/24 = 1/6 part of tank. So, to fill it completely it will take 6 hours. Answer is: d)

Two faucet A and B can fill a tank in 20 hours and 40 hours respectively. If they are opened simultaneously. Sometimes later, tap B was closed, then it takes total 14 hours to fill up the whole tank. After how many hours B was closed? A) 4 hours B) 15.2 hours C) 12 hours D) 17.6 hours

Description : Two faucet A and B can fill a tank in 20 hours and 40 hours respectively. If they are opened simultaneously. Sometimes later, tap B was closed, then it takes total 14 hours to fill up the whole tank. After how many hours B was closed? A) 4 hours B) 15.2 hours C) 12 hours D) 17.6 hours

Last Answer :  A Let x is the time when B is closed X(1/20+1/40)+14/20=1 X=4 hours

3 faucet A,B,C can fill a cistern from empty to full in 45mins, 35mins, and 25 mins respectively. When the cistern is empty all the 3 faucets are opened. A,B,c discharge chemical solutions A,B,C respectively. What is the proportion of solution C in the liquid in the tank after 5 mins? A) 63/143 B) 72/151 c) 67/173 D) 81/167

Description : 3 faucet A,B,C can fill a cistern from empty to full in 45mins, 35mins, and 25 mins respectively. When the cistern is empty all the 3 faucets are opened. A,B,c discharge chemical solutions A,B,C respectively. What is ... the liquid in the tank after 5 mins? A) 63/143 B) 72/151 c) 67/173 D) 81/167

Last Answer : A Part filled by (A+B+C) in 5 mins = 5(1/45 +1/35 + 1/25) = 5 (35+45+63/1575) = 143/315 Part filled by c in 5 mins = 5/25 = 1/5 Required ratio = 1/5 * 315/143 =63/143.

Three pipes P, Q and R can fill a tank from empty to full in 40 minutes, 15 minutes, and 30 minutes respectively. When the tank is empty, all the three pipes are opened. P, Q and R discharge chemical solutions X, Y and Z respectively. What is the proportion of the solution Y in the liquid in the tank after 5 minutes? a) 8 / 15 b) 7 / 15 c) 8 / 17 d) 6 / 13 e) 8 / 13

Description : Three pipes P, Q and R can fill a tank from empty to full in 40 minutes, 15 minutes, and 30 minutes respectively. When the tank is empty, all the three pipes are opened. P, Q and R discharge chemical solutions X, Y and Z respectively. ... 5 minutes? a) 8 / 15 b) 7 / 15 c) 8 / 17 d) 6 / 13 e) 8 / 13

Last Answer : a Part of the tank filled by pipe P in 1 minute = 1 / 40 Part of the tank filled by pipe Q in 1 minute = 1 / 15 Part of the tank filled by pipe R in 1 minute = 1/ 30 Here we have to find the proportion of ... together in 5 minute = 5 1/8 = 5/ 8 Required proportion = (1/3) / ( 5/8) = 8 / 15

A bakery P can sold 500 breads in 4 hours, bakery Q can sold the same number of bread in 5 hrs while bakery R can sold them in 6 hrs. All the bakeries are opened at 8 a.m while bakery P is closed at 9 p.m and the remaining 2 bakeries complete their target. Approximately at what time will the work be finished? a) 10 b) 8 c) 12 d) 6

Description : A bakery P can sold 500 breads in 4 hours, bakery Q can sold the same number of bread in 5 hrs while bakery R can sold them in 6 hrs. All the bakeries are opened at 8 a.m while bakery P is closed ... complete their target. Approximately at what time will the work be finished? a) 10 b) 8 c) 12 d) 6

Last Answer : A (P+Q+R)'s 1 hour work = (1/4 +1/5+ 1/6) =(15+12+10)/60 =37/60 Remaining work = 1- 37/60 = 23/60 (Q+R)'s 1 hour work = (1/5 +1/6) =11/30 Now 11/30 work is done by Q and R ... R in(30/11*23/60) =23/22 hrs = 1hr So the work will be finished approximately 1 hr after 9.am i.e., around 10 a.m

A tank has two faucet which fill it in 15 mins and 18 mins respectively. There is also a waste faucet in the tank. When all the 3 are opened the empty tank is full in 25 mins. How long the waste faucet take to empty the full tank? A) 450/17 mins B) 450/28 mins C) 450/37 mins D) 450/22 mins

Description : A tank has two faucet which fill it in 15 mins and 18 mins respectively. There is also a waste faucet in the tank. When all the 3 are opened the empty tank is full in 25 mins. How long the waste faucet take to empty the full tank? A) 450/17 mins B) 450/28 mins C) 450/37 mins D) 450/22 mins

Last Answer : C Work done by the waste faucet in 1 minute =>1/25 – (1/15 + 1/18) =>1/25 – (6+5/90) = 1/25 – 11/90 => - 37/450 Here negative sign means emptying Therefore waste faucet will empty the full tank in 450/37 mins.

Faucet A basically used as inlet pipe and Faucet B is used as outlet pipe. Faucet A and B both are opened simultaneously, all the time. When Faucet A fills the tank and Faucet B empty the tank, it will take thrice the time than when both the pipes fill the tank. When Faucet B is used for filling the tank, its efficiency remains constant. What is the ratio of efficiency of Faucet A and Faucet B respectively? a) 1:2 b) 2:1 c) 1:3 d) 3:1

Description : Faucet A basically used as inlet pipe and Faucet B is used as outlet pipe. Faucet A and B both are opened simultaneously, all the time. When Faucet A fills the tank and Faucet B empty the tank, it will take thrice the ... efficiency of Faucet A and Faucet B respectively? a) 1:2 b) 2:1 c) 1:3 d) 3:1

Last Answer : B Efficiency when both pipes used to fill = A + B And efficiency when Faucet A is used to fill and Faucet B is used to empty the tank = A-B So (A+B)/(A-B)=3/1 A/B+1/(A/B-1)=3/1 A/B+1=3(A/B-1) 3A/B-A/B=4 2A/B=4 A/B=2 Thus, the ratio of efficiency of Faucet A and B =2:1

Three taps P,Q,R can fill a bunker in 3 hrs. After working at it together for 1 hr, R is closed and P,Q can fill the remaining part in 3 hrs. The number of hrs taken by R alone to fill the bunker. A) 9hrs B) 7hrs C) 11hrs D) 5hrs

Description : Three taps P,Q,R can fill a bunker in 3 hrs. After working at it together for 1 hr, R is closed and P,Q can fill the remaining part in 3 hrs. The number of hrs taken by R alone to fill the bunker. A) 9hrs B) 7hrs C) 11hrs D) 5hrs

Last Answer : A  Part filled in 1 hr = 1/3  Remaining part = 1 – 1/3 = 2/3  (P + Q)’s 3 hours work = 2/3  (P+Q)’s 1 hour work = 2/9  R’s 1 hr work = [(P+Q+R)’s 1 hr work – (P+Q)’s 1 hr work]  = 1/3 – 2/9 = 3-2/9 = 1/9  R alone can fill the tank in 9 hours.

A cistern is filled in 15 hours by three pipes P, Q and R. The pipe R is thrice as fast as Q and Q is thrice as fast as P. How much time will pipe P alone take to fill the tank? A) 120 hrs B) 195 hrs C) 135 hrs D) Cannot be determined

Description : A cistern is filled in 15 hours by three pipes P, Q and R. The pipe R is thrice as fast as Q and Q is thrice as fast as P. How much time will pipe P alone take to fill the tank? A) 120 hrs B) 195 hrs C) 135 hrs D) Cannot be determined 

Last Answer : B Suppose pipe P alone takes x hours to fill the tank. Then, pipes Q and R will take x/3 and x/9hours respectively to fill the tank. 1/x + 3/x + 9/x = 1/15 13/x = 1/15 => x = 195 hrs.

Two pipes A and B can fill a tank in 5 and 6hrs.Pipe C can empty it in 12hrs.If all the 3 pipes are opened together,then the tank will be filled in 1)1(13/17)hrs 2)2(8/11)hours. 3)3(9/17)hrs 4)4(1/2)hrs

Description : Two pipes A and B can fill a tank in 5 and 6hrs.Pipe C can empty it in 12hrs.If all the 3 pipes are opened together,then the tank will be filled in 1)1(13/17)hrs 2)2(8/11)hours. 3)3(9/17)hrs 4)4(1/2)hrs

Last Answer : 3)3(9/17)hrs Exp:Net part filled in 1hr=>(1/5+1/6-1/12)=17/60 Tank filled in=60/17=3(9/17).

Two tap can fill a dumper in 7 hrs and 8 hrs respectively. The taps are opened simultaneously and it is found that due to leakage in the bottom it took 16 mins more to fill the dumper. When the dumper is full, in what time will the leak empty it? A) 56hrs B) 56hrs C) 46hrs D) 36hrs

Description : Two tap can fill a dumper in 7 hrs and 8 hrs respectively. The taps are opened simultaneously and it is found that due to leakage in the bottom it took 16 mins more to fill the dumper. When the dumper is full, in what time will the leak empty it? A) 56hrs B) 56hrs C) 46hrs D) 36hrs

Last Answer : A Work done by 2 taps in 1 hr = (1/7 + 1/8) = 15/56 Time taken by these taps to fill the dumper = 56/15 hrs =3 hrs 44 mins Due to leakage, time taken = 3 hrs +44mins+16 mins =4hrs Work done by (2 ... the leak in 1 hr = (15/56 - ¼) =15 - 4/56 =1/56 Leak will empty the full cistern in 56 hrs.