A stationary engine has enough fuel to run 12 hours when its tank is `4/5` full. How long will it run when the tank is `1/3` full? (a) Less than 2 hours (b) 2 hours (c) 3 hours (d) 4 hours (e) 5 hours

One pipe can fill an empty cistern in 7.8 hours while another can drain the cistern when full in 19.5 hours. Both the pipes were turned on when the cistern was half-empty. How long will it take for the cistern to be full ? a) 3.9 hours b) 7.8 hours c) 6.5 hours d) 5.2 hours

Taps A and B can fill a tank in 2 and 8 hours, respectively. Tap C can empty the filled tank in 4 hours. If all the three taps are turned on simultaneously, how much time will it tank to fill the tank completely? (a)3 hours (b) (9)/(2) hours (c) (3)/(8) hours (d) (8)/(3) hours

A tank has two inlets which can fill it in 4 hours and 6 hours, respectively. An outlet can empty the full tank in 8 hours. Both inlet taps are opened for an hour and closed. Then the three pipes are opened together. The remaining part of the tank fills in : (a) 5(1)/(3) hours (b)2 hours (c) 3(1)/(4) hours (d)3 hours

A tank has two inlets which can fill it in 6 hours and 8 hours, respectively. An outlet can empty the full tank in 10 hours. If all three pipes are opened together in an empty tank how much time will they take to fill the tank completely? (a) 5(5)/(46) hours (b) 6 (5)/(23) hours (c) 6 (5)/(46) hours (d) 5 (5)/(23) hours

If a pipe can empty a full tank in y hours: then part emptied in 1hour.

Taps A and B can fill a tank full in 3 hours. Tap B alone can fill the empty tank in 2 hours. How long will tap A take to vacate the tank if it is 25% filled.

A pipe can fill a tank in x hours and another pipe can empty it in (y:)>backslash x) hours.If both the pipes are open,in how many hours will the tank be filled? (x - y) hours b.(y-x) hours c.(xy)/(x-y) hours d.(xy)/(y-x) hours