Friday, July 3, 2015

#Solve #Puzzle

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?
(1) 39 min                          
(2) 40 min        
(3) 42 min                          

(4) 38 min