Q11. Three pipes A, B and C can fill a tank from empty to full in 30 minutes, 20 minutes and 10 minutes respectively. When the tank is empty, all the three pipes are opened. A, B and C discharge chemical solutions P, Q and R respectively. What is the proportion of solution R in the liquid in the tank after 3 minutes ?
A. 8/11
B. 5/11
C. 6/11
D. 7/11
Q12. A water tank is two-fifth full. Pipe A can fill a tank in 10 minutes and pipe B can empty it in 6 minutes. If both the pipes are open, how long will it take to empty or fill the tank completely ?
A. 6 min, to empty
B. 9min. to empty
C. 9 min. to fill
D. 6 min. to fill
Q13. Pipes A and B can fill a tank in 5 and 6 hours respectively. Pipe C can empty it in 12 hours. If all the three pipes are opened together, then the tank will be filled in :
A. 9/2
B. 60/17
C. 30/11
D. 30/17
Q14. A tank is filled by three pipes with uniform flow. The first two pipes operating simultaneously fill the tank in the same time during which the tank is filled by the third pipe alone. The second pipe fills the tank 5 hours faster than the first pipe and 4 hours slower than the third pipe. The time required by the first pipe is :
A. 6 hrs
B. 15 hrs
C. 10 hrs
D. 30 hrs
Q15. Two pipes A and B can fill a tank in 15 minutes and 20 minutes respectively. Both the pipes are opened together but after 4 minutes, pipe A is turned off. What is the total time required to fill the tank ?
A. 10 min 20 sec
B. 12 min 30 sec
C. 14 min 40 sec
D. 11 min 45 sec
Q16. 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. 35 hrs
B. 20 hrs
C. 30 hrs
D. 25 hrs
