Home

Two pipes A and B can fill a tank in 36 min. and 45 min. respectively. A water pipe C can empty the tank in 30 min. First A and B are opened. after 7 min,C is also opened. In how much time, the tank is full?

A. 39 min

B. 40 min

C. 50 min

D. 45min

Please do not use chat terms. Example: avoid using "grt" instead of "great".