Quantitative Aptitude

General Questions

11.  A tank is filled in 5 hours by three pipes A, B and C. The pipe C is twice as fast as B and B is twice as fast as A. How much time will pipe A alone take to fill the tank?

A. 20 hours
B. 25 hours
C. 35 hours
D. Cannot be determined
E. None of these
12.  A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?

A. 3 hrs 15 min
B. 3 hrs 45 min
C. 4 hrs
D. 4 hrs 15 min
13.  Two pipes A and B together can fill a cistern in 4 hours. Had they been opened separately, then B would have taken 6 hours more than A to fill the cistern. How much time will be taken by A to fill the cistern separately?

A. 1 hour
B. 2 hour
C. 6 hour
D. 8 hour
14.  Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for one hour each alternately, the tank will be full in:

A. 6 hours
B. 6(2/3) hours
C. 7 hours
D. 7(1/2) hours
15.  Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is:

A. 10
B. 12
C. 14
D. 16