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:
A2(8/11) hours
B3(9/17)hours
C4(1/2) hours
D11(3/17)hours
সঠিক উত্তর:B.3(9/17)hours

