The detention period in a septic tank is assumed (A) 20 minutes (B) 25 minutes (C) 30 minutes (D) 40 minute

The detention period in a septic tank is assumed
(A) 20 minutes
(B) 25 minutes
(C) 30 minutes
(D) 40 minute
by

1 Answer

Answer :

(C) 30 minutes
by

Related questions

For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is A. 16 m B. 20 m C. 24 m D. 30 m

Description : For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is A. 16 m B. 20 m C. 24 m D. 30 m

Last Answer : ANS: C

An intense rain is falling at a uniform rate of 7.5 cm/hour for a period of 60 minutes on a basin whose area is 500 hectares. If the average infiltration capacity during the entire rain period is assumed to be 1.5 cm/hr, the maximum run-off rate based on 10 minute peak percentage of 16% from distributing graph of the basin, is (A) 40 cumecs (B) 60 cumecs (C) 80 cumecs (D) 100 cumecs

Description : An intense rain is falling at a uniform rate of 7.5 cm/hour for a period of 60 minutes on a basin whose area is 500 hectares. If the average infiltration capacity during the entire rain period is assumed to be 1.5 ... of the basin, is (A) 40 cumecs (B) 60 cumecs (C) 80 cumecs (D) 100 cumecs

Last Answer : Answer: Option C

The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is A. 30 minutes B. 1 hour C. 1 hour and 30 minutes D. 2 hours

Description : The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is A. 30 minutes B. 1 hour C. 1 hour and 30 minutes D. 2 hours

Last Answer : ANS: D

The recommended detention period for grit chambers is A. 1 minute B. 2 minutes C. 3 minutes D. 5 minutes

Description : The recommended detention period for grit chambers is A. 1 minute B. 2 minutes C. 3 minutes D. 5 minutes

Last Answer : ANS: A

In case of Imhoff tanks, A. The shape is rectangular B. Detention period is 2 hours C. The velocity of flow is restricted to 0.30 m/minute D. All the above

Description : In case of Imhoff tanks, A. The shape is rectangular B. Detention period is 2 hours C. The velocity of flow is restricted to 0.30 m/minute D. All the above

Last Answer : ANS: D

Three pipes, A, B, & C are attached to a tank. A & B can fill it in 20 & 30 minutes respectively while C can empty it in 15 minutes. If A, B & C are kept open successively for 1 minute each, how soon will the tank be filled?

Description : Three pipes, A, B, & C are attached to a tank. A & B can fill it in 20 & 30 minutes respectively while C can empty it in 15 minutes. If A, B & C are kept open successively for 1 minute each, how soon will the tank be filled?

Last Answer : Answer: 167 minutes.

In a grit chamber of a sewage treatment plant, A. Flow velocity 0.15 m to 0.3 m/sec is kept B. Depth of 0.9 m to 1.20 m is kept C. One minute of detention period is kept D. All the above

Description : In a grit chamber of a sewage treatment plant, A. Flow velocity 0.15 m to 0.3 m/sec is kept B. Depth of 0.9 m to 1.20 m is kept C. One minute of detention period is kept D. All the above

Last Answer : ANS: D

Pick up the incorrect statement from the following: A. Septic tanks are horizontal continuous flow type of sedimentation tanks B. Septic tanks are generally provided a detention period of 12 to 36 hours C. Septic tanks are completely covered and high vent shafts are provided for the escape of foul gases D. None of these

Description : Pick up the incorrect statement from the following: A. Septic tanks are horizontal continuous flow type of sedimentation tanks B. Septic tanks are generally provided a detention period of 12 to 36 hours C ... covered and high vent shafts are provided for the escape of foul gases D. None of these

Last Answer : ANS: D

Pick up the correct statement from the following: (A) Detention period for plain sedimentation tanks ranges between 4 to 8 hours (B) Detention period for sedimentation tanks, using coagulants usually ranges between 2 to 4 hours(C) The horizontally flow velocity in sedimentation tanks, is generally limited to 0.3 m/minute (D) All the above

Description : Pick up the correct statement from the following:  (A) Detention period for plain sedimentation tanks ranges between 4 to 8 hours  (B) Detention period for sedimentation tanks, using coagulants usually ... in sedimentation tanks, is generally limited to 0.3 m/minute  (D) All the above

Last Answer : (D) All the above

In a sedimentation tank, the detention period for water ranges from __________ hours. (A) 2 to 4 (B) 8 to 12 (C) 16 to 20 (D) 24 to 32

Description : In a sedimentation tank, the detention period for water ranges from __________ hours. (A) 2 to 4 (B) 8 to 12 (C) 16 to 20 (D) 24 to 32

Last Answer : (A) 2 to 4

The efficiency of sedimentation tank does not depend upon (A) Depth of tank (B) Length of tank (C) Detention period (D) Velocity of water

Description : The efficiency of sedimentation tank does not depend upon  (A) Depth of tank  (B) Length of tank  (C) Detention period  (D) Velocity of water

Last Answer : (D) Velocity of water

Detention period of a settling tank is (A) Average theoretical time required for water to flow through the tank (B) Time required for flow of water to fill the tank fully (C) Average time for which water is retained in tank (D) All the above

Description : Detention period of a settling tank is  (A) Average theoretical time required for water to flow through the tank  (B) Time required for flow of water to fill the tank fully  (C) Average time for which water is retained in tank  (D) All the above

Last Answer : (D) All the above

The total domestic consumption in a city water supply, is assumed (A) 20 % (B) 30 % (C) 40 % (D) 60 %

Description : The total domestic consumption in a city water supply, is assumed (A) 20 % (B) 30 % (C) 40 % (D) 60 %

Last Answer : (D) 60 %

Pipe A can fill an empty tank in 20 minutes and Pipe B in 30 mins and Pipe C can empty the same in 40 mins. If all of them work together, find the time taken to fill the tank? (a) 17 1/7 mins (b) 20 mins (c) 8 mins (d) none of these

Description : Pipe A can fill an empty tank in 20 minutes and Pipe B in 30 mins and Pipe C can empty the same in 40 mins. If all of them work together, find the time taken to fill the tank? (a) 17 1/7 mins (b) 20 mins (c) 8 mins (d) none of these

Last Answer : (a) 17 1/7 mins

Velocity of flow of water in plain sedimentation water tank, is normally kept (A) 3 cm/minute (B) 10 cm/minute (C) 20 cm/minute (D) 30 cm/minute

Description : Velocity of flow of water in plain sedimentation water tank, is normally kept  (A) 3 cm/minute  (B) 10 cm/minute  (C) 20 cm/minute  (D) 30 cm/minute 

Last Answer : (D) 30 cm/minute 

Two pipes can fill a tank in 20 and 24 minutes respectively and another pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank in gallons is: a)100 b)110 c)120 d)140

Description : Two pipes can fill a tank in 20 and 24 minutes respectively and another pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank in gallons is: a)100 b)110 c)120 d)140

Last Answer : c)120

The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is A. 204 cu.m B. 208 cu.m C. 212 cu.m D. 216 cu.m

Description : The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is A. 204 cu.m B. 208 cu.m C. 212 cu.m D. 216 cu.m

Last Answer : ANS: D

The width of a settling tank with 2 hour detention period for treating sewage 378 cu m per hour, is A. 5 m B. 5.5 m C. 6.5 m D. 7 m

Description : The width of a settling tank with 2 hour detention period for treating sewage 378 cu m per hour, is A. 5 m B. 5.5 m C. 6.5 m D. 7 m

Last Answer : ANS: D

In detritus tanks, A. Flow velocity is kept 0.09 m/sec B. Detention period is kept 3 to 4 minutes C. Organic and inorganic materials are separated D. All the above

Description : In detritus tanks, A. Flow velocity is kept 0.09 m/sec B. Detention period is kept 3 to 4 minutes C. Organic and inorganic materials are separated D. All the above

Last Answer : ANS: D

Detention time for plain sedimentation tank usually ranges from (A) 2 to 4 hours (B) 4 to 8 hours (C) 6 to 10 hours (D) 8 to 12 hours

Description : Detention time for plain sedimentation tank usually ranges from (A) 2 to 4 hours (B) 4 to 8 hours (C) 6 to 10 hours (D) 8 to 12 hours

Last Answer : (B) 4 to 8 hours

A well penetrates to 30 m below the static water table. After 24 hours of pumping at 31.40 litres/minute, the water level in a test well at a distance of 80 m is lowered by 0.5 m and in a well 20 m away water is lowered by 1.0 m. The transmissibility of the aquifer, is (A) 1.185 m2 /minute(B) 1.285 m2/minute (C) 1.385 m2/minute (D) 1.485 m2/minute

Description : A well penetrates to 30 m below the static water table. After 24 hours of pumping at 31.40 litres/minute, the water level in a test well at a distance of 80 m is lowered by 0.5 m and in a well 20 m away water is ... 1.185 m2 /minute (B) 1.285 m2 /minute (C) 1.385 m2 /minute (D) 1.485 m2 /minute

Last Answer : Answer: Option C

A barrier has four inlets A, B, C and D. The barrier can be filled in 24 minutes through the first three inlets and it can be filled in 30 minutes through the second, the third and fourth inlet also it can be filled through the first and the fourth inlet in 40 minutes. How much time required to fill up the barrier by all the four inlets? A) 10 mins B) 15 mins C) 20 mins D) 25 mins E) None of the Above

Description : A barrier has four inlets A, B, C and D. The barrier can be filled in 24 minutes through the first three inlets and it can be filled in 30 minutes through the second, the third and fourth inlet also it can be ... all the four inlets? A) 10 mins B) 15 mins C) 20 mins D) 25 mins E) None of the Above

Last Answer : C (1/A + 1/B + 1/C) = 1/24 …(i) (1/B + 1/C + 1/D) = 1/30 …(ii) (1/A + 1/D) = 1/40…(iii) From eqn (i) and (ii) (1/A – 1/D) = 1/120…(iv) From eqn (iii) and (iv) A=60,D=120. Let the time taken to full the tank = s S(1/A + 1/B +1/C +1/D)= 1 S(1/24+1/120) = 1 S= 20 mins

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

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

The duration of contact of chlorine with water before it is served to the first consumer, should be at least (A) 10 to 15 minutes (B) 15 to 20 minutes (C) 20 to 30 minutes (D) 30 to 40 minutes

Description : The duration of contact of chlorine with water before it is served to the first consumer, should be  at least  (A) 10 to 15 minutes  (B) 15 to 20 minutes  (C) 20 to 30 minutes  (D) 30 to 40 minutes 

Last Answer : (C) 20 to 30 minutes 

A can type 30 words in 1 minutes and B can type 20 words in 1 minute. Both A and B can type …………….. Words in 1 minute.

Description : A can type 30 words in 1 minutes and B can type 20 words in 1 minute. Both A and B can type …………….. Words in 1 minute.

Last Answer : A can type 30 words in 1 minutes and B can type 20 words in 1 minute. Both A and B can type …………….. Words in 1 minute.

What is the time of useful consciousness at 20,000 feet (moderate activity)? a. 5 minutes b. 1 minute c. 10 minutes d. 30 seconds

Description : What is the time of useful consciousness at 20,000 feet (moderate activity)? a. 5 minutes b. 1 minute c. 10 minutes d. 30 seconds

Last Answer : a. 5 minutes

What is the time of useful consciousness at 20,000 feet (moderate activity)? a. 5 minutes b. 1 minute c. 10 minutes d. 30 seconds

Description : What is the time of useful consciousness at 20,000 feet (moderate activity)? a. 5 minutes b. 1 minute c. 10 minutes d. 30 seconds

Last Answer : a. 5 minutes

The minimum width of a septic tank is taken (A) 70 cm (B) 75 cm (C) 80 cm (D) 90 c

Description : The minimum width of a septic tank is taken (A) 70 cm (B) 75 cm (C) 80 cm (D) 90 c

Last Answer : (B) 75 cm

While designing a water supply of an industrial township, industrial and commercial water demand of total supply, is assumed (A) 10 % (B) 10 to 15 % (C) 15 to 20 % (D) 20 to 25 %

Description : While designing a water supply of an industrial township, industrial and commercial water  demand of total supply, is assumed  (A) 10 %  (B) 10 to 15 %  (C) 15 to 20 %  (D) 20 to 25 %

Last Answer : (D) 20 to 25 %

A rectangle-shaped open-to-sky tank of water has a length of 2 m and a width of 1 m. If the atmospheric pressure is assumed to be 100 kPa and thickness of the tank walls is assumed to be negligible, the force exerted by the atmosphere on the surface of water is A. 20 kN B. 50 kN C. 100 kN D. 200 kN

Description : A rectangle-shaped open-to-sky tank of water has a length of 2 m and a width of 1 m. If the atmospheric pressure is assumed to be 100 kPa and thickness of the tank walls is assumed to be negligible, the force exerted by ... of water is A. 20 kN B. 50 kN C. 100 kN D. 200 kN

Last Answer : 200 kN

Three pumps, M, N and O are opened to fill a tank such that M and N can fill the tank alone in 18 min. and 23 min. respectively and O can empty it in 15 min. After 3 minutes the emptying pipe is closed. In how many minutes the tank will be full in this way? A) 20 B) 25 C) 18 D) 12

Description : Three pumps, M, N and O are opened to fill a tank such that M and N can fill the tank alone in 18 min. and 23 min. respectively and O can empty it in 15 min. After 3 minutes the emptying pipe is closed. In how many minutes the tank will be full in this way? A) 20 B) 25 C) 18 D) 12

Last Answer : D Let the tank full in x minutes, then M and N opened for x minutes and O for 3 minutes. (1/18 + 1/23)*x – (1/15)*3 = 1 (23+18/414)X=1+1/5 Solve, x = 12

For calculating the tractive force along an upgrade of an asphalt road, the most probable value of the co-efficient of traction resistance is assumed (A) 1/10 (B) 1/20 (C) 1/30 (D) 1/100

Description : For calculating the tractive force along an upgrade of an asphalt road, the most probable value of the co-efficient of traction resistance is assumed (A) 1/10 (B) 1/20 (C) 1/30 (D) 1/100

Last Answer : Answer: Option D

Minimum horsepower of pump required for filling 50m3 water tank, 20 metres high from ground in 30 minutes by lifting water from a well 5 metres below the ground level is a.5.45 KW b.7.5 KW c.6.81 KW d.Tapered bearing e.66.8 KW

Description : Minimum horsepower of pump required for filling 50m3 water tank, 20 metres high from ground in 30 minutes by lifting water from a well 5 metres below the ground level is a.5.45 KW b.7.5 KW c.6.81 KW d.Tapered bearing e.66.8 KW

Last Answer : c. 6.81 KW

In sewage treatment, the detention period allowed for oxidation ponds ranges from __________ weeks. (A) 1 to 2 (B) 4 to 5 (C) 9 to 10 (D) 15 to 20

Description : In sewage treatment, the detention period allowed for oxidation ponds ranges from __________ weeks. (A) 1 to 2 (B) 4 to 5 (C) 9 to 10 (D) 15 to 20

Last Answer : (B) 4 to 5

Flow through period, in sedimentation tanks, is (A) Equal to detention period (B) More than detention period (C) Less than detention period (D) Detention period divided by displacement efficiency

Description : Flow through period, in sedimentation tanks, is  (A) Equal to detention period  (B) More than detention period  (C) Less than detention period  (D) Detention period divided by displacement efficiency 

Last Answer : (C) Less than detention period 

The detention period for plain sedimentation water tanks, is usually (A) 4 to 8 hours (B) 8 to 16 hours (C) 16 to 24 hours (D) 24 to 36 hours

Description : The detention period for plain sedimentation water tanks, is usually  (A) 4 to 8 hours  (B) 8 to 16 hours  (C) 16 to 24 hours  (D) 24 to 36 hours

Last Answer : (D) 24 to 36 hours

The detention time (t) of a settling tank, may be defined as the time required for A. A particle to travel along its length B. A particle to travel from top surface to bottom sludge zone C. The flow of sewage to fill the tank D. None of these

Description : The detention time (t) of a settling tank, may be defined as the time required for A. A particle to travel along its length B. A particle to travel from top surface to bottom sludge zone C. The flow of sewage to fill the tank D. None of these

Last Answer : ANS: C

The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is A. d² (0.011d + 0.785H)/Q B. d (0.022d + 0.085H)/Q C. d (0.785d + 0.011H)/Q D. d (0.285d + 0.011H)/Q

Description : The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is A. d² (0.011d + 0.785H)/Q B. d (0.022d + 0.085H)/Q C. d (0.785d + 0.011H)/Q D. d (0.285d + 0.011H)/Q

Last Answer : ANS: A

The percentage of chlorine in fresh bleaching powder is roughly (A) 50 to 60 (B) 30 to 35 (C) 40 to 50 (D) 20 to 25

Description : The percentage of chlorine in fresh bleaching powder is roughly (A) 50 to 60 (B) 30 to 35 (C) 40 to 50 (D) 20 to 25

Last Answer : (B) 30 to 35

The resultant of the following three couples 20 kg force, 0.5 m arm, +ve sense 30 kg force, 1 m arm, -ve sense 40 kg force, 0.25 m arm, +ve sense having arm of 0.5 m will be (A) 20 kg, -ve sense (B) 20 kg, +ve sense (C) 10 kg, +ve sense (D) 10 kg, -ve sense

Description : The resultant of the following three couples 20 kg force, 0.5 m arm, +ve sense 30 kg force, 1 m  arm, -ve sense 40 kg force, 0.25 m arm, +ve sense having arm of 0.5 m will be  (A) 20 kg, -ve sense  (B) 20 kg, +ve sense  (C) 10 kg, +ve sense  (D) 10 kg, -ve sense 

Last Answer : (A) 20 kg, -ve sense

The peak of a 4 hour flood hydrograph is 240 m3 /sec. If the rainfall excess is 80 mm and base flow which is constant is 40 m3 /sec, peak of 4hours unit hydrograph will be (A) 20 m3 /sec (B) 25 m3 /sec (C) 30 m3 /sec (D) 35 m3 /sec

Description : The peak of a 4 hour flood hydrograph is 240 m3 /sec. If the rainfall excess is 80 mm and base flow which is constant is 40 m3 /sec, peak of 4hours unit hydrograph will be (A) 20 m3 /sec (B) 25 m3 /sec (C) 30 m3 /sec (D) 35 m3 /sec

Last Answer : Answer: Option B

Minimum clear cover (in mm) to the main steel bars in slab, beam, column and footing respectively, are (a) 10, 15, 20 and 25 (b) 15, 25, 40 and 75 (c ) 20, 25, 30 and 40 (d) 20, 35, 40 and 75

Description : Minimum clear cover (in mm) to the main steel bars in slab, beam, column and footing respectively, are (a) 10, 15, 20 and 25 (b) 15, 25, 40 and 75 (c ) 20, 25, 30 and 40 (d) 20, 35, 40 and 75

Last Answer : (b) 15, 25, 40 and 75

Which of the following statements about septic shock are true? A. A circulating myocardial depressant factor may account for the cardiac dysfunction sometimes seen with shock due to sepsis or SIRS. B. A cardiac index (CI) of 6 liters per minute per square meter of body surface, a pulmonary capillary wedge pressure of 15 mm. Hg, and a systemic vascular resistance index (SVRI) of 800 dynes-sec/(cm 5-m 2) is a hemodynamic profile consistent with septic shock. C. An increase in SvO 2 in septic patients may be explained by the finding of anatomic arteriovenous shunts. D. Results of human trials employing antimediator therapy, such as antiendotoxin antibodies, IL-1 receptor antagonist, and tumor necrosis factor (TNF) antibodies, have confirmed animal studies that demonstrate a significant im

Description : Which of the following statements about septic shock are true? A. A circulating myocardial depressant factor may account for the cardiac dysfunction sometimes seen with shock due to sepsis or ... animal studies that demonstrate a significant improvement in survival with the use of such agents.

Last Answer : Answer: AB DISCUSSION: Shock due to sepsis or SIRS frequently manifests as a hyperdynamic cardiovascular response, consisting of an elevated CI and a decreased SVR or SVRI. Occasionally, ... been encouraging thus far in human clinical trials, despite the promising results from many animal studies

The rate of accumulation of sludge in septic tanks is recommended as A. 30 litres/person/year B. 25 litres/person/year C. 30 litres/person/month D. 25 litres/person/month

Description : The rate of accumulation of sludge in septic tanks is recommended as A. 30 litres/person/year B. 25 litres/person/year C. 30 litres/person/month D. 25 litres/person/month

Last Answer : ANS: A

A car covers a distance of 1120 metres in 1 minute whereas a bus covers a distance of 56 kms in 44 minutes. What is the ratio of their speed? a) 22:25 b) 25:22 c) 11:15 d) 15:11

Description : A car covers a distance of 1120 metres in 1 minute whereas a bus covers a distance of 56 kms in 44 minutes. What is the ratio of their speed? a) 22:25 b) 25:22 c) 11:15 d) 15:11

Last Answer : A Speed of the Car = 1120 m/minute Speed of the bus=56 kms in 44 minutes =56/44 km/m =56000/44 m/mints Speed of the car : Speed of the bus, =1120:56000/44 =280:14000/44 =20:1000/44 =880:1000 =88:100 Required ratio =22:25

A tank is 1/4th full. Two pipes which fill the tank in 30minutes and 40 minutes respectively are opened simultaneously. After 10 minutes, a third pipe which empties the full tank in 60 minutes is also opened. In how many minutes the tank will be full? A) 14 B) 12 C) 15 D) 17

Description : A tank is 1/4th full. Two pipes which fill the tank in 30minutes and 40 minutes respectively are opened simultaneously. After 10 minutes, a third pipe which empties the full tank in 60 minutes is also opened. In how many minutes the tank will be full? A) 14 B) 12 C) 15 D) 17

Last Answer : A Since 1/4th is already filled, 3/4th is to filled now. (1/30 + 1/40)*(10+x) – (1/60)*x = ¾ 7/120(10+x)-x/60=3/4 7x-2x/120=3/4-7/12 5x/120=1/6 30x=120 X=4 So total 10+4=14minutes

A,B are start walking around a Circular park of radius 70m. They start at the same point, and A goes clockwise at 10m/s, while b goes anti-clockwise at 20m/s.How many times will they cross each other at the starting point if they walk for 30 minutes? a) 20 b) 40 c) 60 d) 80 e) None of the above

Description : A,B are start walking around a Circular park of radius 70m. They start at the same point, and A goes clockwise at 10m/s, while b goes anti-clockwise at 20m/s.How many times will they cross each other at the starting point if they walk for 30 minutes? a) 20 b) 40 c) 60 d) 80 e) None of the above

Last Answer : Radius = 70m, So circumference = 2 (22/7) 70 =440m Relative speed = 10 +20 = 30m/s They will meet everytime at the starting point when the distance covered by both put together is a multiple of 440 ... =1800/44 =40.9 So they will meet 40 times (we need to ignore the decimal part). Answer : b