Question (9/28)
Large tanker can be filled by two pipes A and B in 60 minutes and 40 minutes respectively. How many minutes will it take to fill tanker from empty state if B is used for half the time and A and B fill it together for the other half ?(A)  20 minutes
(B)  30 minutes
(C)  35 minutes
(D)  40 minutes
Question (10/28)
Two pipes A and B can fill a tank in 15 hours and 20 hours respectively. Third pipe C can empty the full tank in 25 hours. All the 3 pipes are opened in the beginning. After 10 hours pipe C is closed. In how much time will the tank be full ?(A)  12 Hours
(B)  14 Hours
(C)  16 Hours
(D)  18 Hours