40
Q:

# Two pipes can fill a tank in 20 and 24 minutes respectively and a waste 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 is:

 A) 60 gallons B) 100 gallons C) 120 gallons D) 180 gallons

Explanation:

Work done by the waste pipe in 1 minute = [-ve sign means emptying]

Volume of $140$part = 3 gallons

Volume of whole = (3 x 40) gallons = 120 gallons.

Q:

Pipes A and B can fill a tank in 10 hours and 40 hours, respectively. C is an outlet pipe attached to the tank. If all the three pipes are opened simultaneously, it takes 80 minutes more time than what A and B together take to fill the tank. A and B are kept opened for 7 hours and then closed and C was opened. C will now empty the tank in:

 A) 49 hours B) 38.5 hours C) 42 hours D) 45.5 hours

Explanation:

2 280
Q:

Pipe A can fill an empty cistern in 15 hours while Pipe B takes 25 hours to fill it. Initially Pipe A is left open for some time and then closed and Pipe B is switched on immediately. In all the cistern rakes 21 hours to be filth How long was Pipe A open?

 A) 3 hours B) 7.5 hours C) 6 hours D) 9 hours

Explanation:

0 479
Q:

Pipes A, B and C together can fill a tank in 4 hours. Pipes A and B together can fill the tank in 9 hours. If pipes A, B and C are opened simultaneously, and after 3 hours, pipes A and B are closed, then how many hours will C alone require to fill the tank?

 A) 2.25 B) 2 C) 1.5 D) 1.8

Explanation:

1 336
Q:

Pipes A and C can fill an empty cistern in 7 and 10.5 hours, respectively while Pipe B can drain the filled cistern in 5.25 hours. If the three pipes are turned on together when the cistern is empty, how many hours will it take for the cistern to be$23$full?

 A) 121 B) 12 C) 14 D) 15.75

Explanation:

2 298
Q:

Pipes A, B and C are attached to an empty cistern. While the first two can fill the cistern in 6.6 and 16.5 hours respectively, the third can drain the cistern, when filled, in 9.9 hours. If all the three pipes are opened simultaneously when the cistern is three-fifths full, how many hours will be needed to fill the cistern?

 A) 3.5 B) 4 C) 3.6 D) 3.75

Explanation:

0 329
Q:

Two pipes A and B can fill an empty cistern in 1.8 and 2.7 hours, respectively. Pipe C can drain the entire cistern in 4.5 hours when no other pipe is in operation. Initially when the cistern was empty Pipe A and  Pipe C were turned on. After a few hours Pipe A was turned off and Pipe B was turned on instantly. In all it took 5.5 hours to fill the cistern. For how many hours was Pipe B turned on?

 A) 5 B) 4.5 C) 3 D)

Explanation:

0 390
Q:

Pipe A could fill an empty cistern in 18 hrs while pipe B can drain a filled cistern in 30 hrs. When the cistern is empty, pipe A is turned on for an hour and then turned off. The pipes were alternately left open for an hour each time till the cistern was full. How much time did it take for the cistern to be full?

 A) 90 hrs B) 86 hrs 40 min C) 45 hrs D) 86 hrs 48 min

Explanation:

0 371
Q:

Pipe A can fill an empty cistern in 6 hours while along with Pipe B it can fill it up in 4 hours. Only Pipe B is on for an hour after which Pipe A is also turned on. How much time will it take in all to fill up the cistern?

 A) 4 hrs 25 min B) 4 hrs 15 min C) 4 hrs 40 min D) 4 hrs