Ashok can row upstream at 8kmph and downstream at 12kmph.What is the speed of the stream ? A.6km/hr B.3km/h C.2 km/hr D.4km/hr

Ashok can row upstream at 8kmph and downstream at 12kmph.What is the speed of the stream ? A.6km/hr B.3km/h C.2 km/hr D.4km/hr
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1 Answer

Answer :

Answer -C

Basic Formula:

If the speed downstream is a kmph and the speed upstream is b kmph

then

Speed of the stream = ½ (a-b) kmph

Explanation:

Speed downstream a = 12kmph

Speed upstream b = 8 kmph

Speed of the stream = ½ (a-b) = ½ (12-8)

= 4/2 = 2 kmph

speed of the stream = 2kmph
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Related questions

A man rows to a place 48km distant and back in 14 hours. He finds that he can row 4km with the stream in the same time as 3km against the stream. Find the rate of the stream. A.2 km/hr B.1 km/hr C.3 km/hr D.3.5km/hr

Description : A man rows to a place 48km distant and back in 14 hours. He finds that he can row 4km with the stream in the same time as 3km against the stream. Find the rate of the stream. A.2 km/hr B.1 km/hr C.3 km/hr D.3.5km/hr

Last Answer : Answer- B Basic Formula: Speed of the stream = ½ (a-b) km / hr Speed = distance traveled / time taken Explanation: Suppose he moves 4km downstream in x hours Then, downstream a= 4 / x km/hr Speed upstream b = 3/ x km/hr ... = 1/2 a=8 km/hr ,b = 6 km/hr rate of stream = ½ (8 - 6 ) = 1 km/hr

A boat takes 4hours for traveling downstream from point P to point Q and coming back to point P upstream. If the velocity of the stream is 2km ph and the speed of the boat in still water is 4kmph, what is the distance between P and Q? A.9 km B.7 km C.5 km D.6km

Description : A boat takes 4hours for traveling downstream from point P to point Q and coming back to point P upstream. If the velocity of the stream is 2km ph and the speed of the boat in still water is 4kmph, what is the distance between P and Q? A.9 km B.7 km C.5 km D.6km

Last Answer : Answer- D Basic Formula: Speed of stream = ½ (a-b) km/hr Speed of still water = ½ (a+b) km/hr Explanation: Time taken by boat to travel upstream and downstream = 4 hours Velocity of the stream, ½ (a-b) = 2km/hr a ... + x / 6 = 4 3x + x / 6 = 4 4x = 24 so,x = 6 distance between P and Q = 6km

A man rows 750m in 775 seconds against the stream and returns in 7 1/2 minutes. What is rowing speed in still water ? A.4.7km/hr B. 4km/hr C.3.5km/hr D.6km/hr

Description : A man rows 750m in 775 seconds against the stream and returns in 7 1/2 minutes. What is rowing speed in still water ? A.4.7km/hr B. 4km/hr C.3.5km/hr D.6km/hr

Last Answer : Answer-A Basic Formula: i) Speed in still water = ½ (a+b) kmph where a' is speed downstream and b' is speed upstream ii) a km / hr = a x 5/18 m /s iii) a m/sec = a x 18/5 km/hr Explanation: Speed upstream b' ... (750/450 + 750/675 ) x 18/5 km/hr = ½ (5/3 + 30/31) x 18/5 km/hr = 4.7 km/hr

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Description : If Nishu can swim downstream at 6kmph and upstream at 2kmph.What is his speed in still water ? A.5 km/hr B.4 km/hr C.8km/hr D.7km/hr

Last Answer : Answer- B Basic Formula: If the speed downloadstream is a km/ hr and the speed upstream is b km/ hr then Speed in still water is = ½ (a+b) km / hr [memory tool last 2 L cross and make +] Explanation: Given ... still water = ½ (a+b) kmph = ½ (6+2) = 8/2 = 4kmph speed in still water = 4kmph

A boat goes 30 km upstream and 44 km downstream in 10 hours. In 13 hours it can go 40 km upstream and 55 km downstream. Then what is the speed of the stream? (a) 3km/hr (b) 5km/hr (c) 6km/hr (d) 7km/hr

Description : A boat goes 30 km upstream and 44 km downstream in 10 hours. In 13 hours it can go 40 km upstream and 55 km downstream. Then what is the speed of the stream? (a) 3km/hr (b) 5km/hr (c) 6km/hr (d) 7km/hr

Last Answer : (a) 3km/hr

A boat goes 30 km upstream and 44 km downstream in 10 hours. In 13 hours it can go 40 km upstream and 55 km downstream. Then what is the speed of the stream? (a) 3km/hr (b) 5km/hr (c) 6km/hr (d) 7km/hr

Description : A boat goes 30 km upstream and 44 km downstream in 10 hours. In 13 hours it can go 40 km upstream and 55 km downstream. Then what is the speed of the stream? (a) 3km/hr (b) 5km/hr (c) 6km/hr (d) 7km/hr

Last Answer : (a) 3km/hr

A boat running downstream covers a distance of 20 km in 5 hours while for covering the same distance upstream, it takes 10 hours. What is the speed of the stream? a) 2km/hr b) 4km/hr c) 1km/hr d) 1.5 km/hr e) None of these

Description : A boat running downstream covers a distance of 20 km in 5 hours while for covering the same distance upstream, it takes 10 hours. What is the speed of the stream? a) 2km/hr b) 4km/hr c) 1km/hr d) 1.5 km/hr e) None of these

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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

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A 270 m long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train? A.180 B.230 C.245 D.235 E.None of these

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Two, trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is: A. 1: 2 B. 4 : 3 C. 7 : 8 D. 3 : 4 E. none of these

Description : Two, trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is: A. 1: 2 B. 4 : 3 C. 7 : 8 D. 3 : 4 E. none of these

Last Answer : Answer- B (4:3) Explanation: Let us name the trains as A and B. Then, trick formula (A’s speed) : (B’s speed) = square root of b : square-root of a =square-root of 16 : square-root of 9 = 4 : 3.

Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is: A.1 : 3 B.3 : 4 C.3 : 2 D.Data inadequate E.None of these

Description : Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and  they cross each other in 23 seconds. The ratio of their speeds is: A.1 : 3 B.3 : 4 C.3 : 2 D.Data inadequate E.None of these

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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

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 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 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 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

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

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

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 

Distance between two stations P & Q is 1556km. A passenger train covers the journey from P to Q at 168km per hr and return back to P with a uniform speed of 112km/hr. Find the Average speed of the train during the whole journey? A) 124.4 km/hr B) 130.4km/hr C) 134.4 km/hr D) 130.0 km/hr

Description : Distance between two stations P & Q is 1556km. A passenger train covers the journey from P to Q at 168km per hr and return back to P with a uniform speed of 112km/hr. Find the Average speed of the train during the whole journey? A) 124.4 km/hr B) 130.4km/hr C) 134.4 km/hr D) 130.0 km/hr

Last Answer : C) Given x= 168 , y = 112 Required average speed = (2xy / x + y) km/hr = 2 * 168 *112 / 168 + 112 = 37632 / 280 =134.4 km/hr

A boat covers 14 kms in upstream and 20 kms downstream in 7 hours. Also it covers 22 kms upstream and 34 kms downstream in 10 hours. Find the speed of the boat in still water and of that the stream. -Maths 9th

Description : A boat covers 14 kms in upstream and 20 kms downstream in 7 hours. Also it covers 22 kms upstream and 34 kms downstream in 10 hours. Find the speed of the boat in still water and of that the stream. -Maths 9th

Last Answer : Given, The boat covers 14 km upstream and 20km downstream . at time 7 hours also cover 22km ups. and 34km dwn in10 hours total speed = total distance/total time :.total distance = 14+20+22+34=90km and total time=7+10= ... =90/17 => 5.294km/h => 5.294km/h the speed of boat in still water is 5.29 km/h

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

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

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.

Refer to the following TAF for Zurich LSZH 261019 20018G30KT 9999 –RA SCT050 BKN080 TEMPO 23012KT 6000 –DZ BKN015 BKN030 BECMG 1518 23020G35KT 4000 RA OVC010= The lowest visibility forecast at ETA Zurich 1430 UTC is: a. 6km b. 6nm c. 4km d. 10km

Description : Refer to the following TAF for Zurich   LSZH 261019 20018G30KT 9999 –RA SCT050 BKN080 TEMPO 23012KT 6000 –DZ  BKN015 BKN030 BECMG 1518 23020G35KT 4000 RA OVC010=  The lowest visibility forecast at ETA Zurich 1430 UTC is:  a. 6km  b. 6nm  c. 4km  d. 10km

Last Answer : a. 6km

Refer to the following TAF for Zurich LSZH 261019 20018G30KT 9999 –RA SCT050 BKN080 TEMPO 23012KT 6000 –DZ BKN015 BKN030 BECMG 1518 23020G35KT 4000 RA OVC010= The lowest visibility forecast at ETA Zurich 1430 UTC is: a. 6km b. 6nm c. 4km d. 10km

Description : Refer to the following TAF for Zurich LSZH 261019 20018G30KT 9999 –RA SCT050 BKN080 TEMPO 23012KT 6000 –DZ BKN015 BKN030 BECMG 1518 23020G35KT 4000 RA OVC010= The lowest visibility forecast at ETA Zurich 1430 UTC is: a. 6km b. 6nm c. 4km d. 10km

Last Answer : a. 6km