A tap can fill a tank in 32 min. and another can empty it in 16 min.  If the tank is already half full and both the tanks are opened together, the tank will be_________?

A. 12 min
B. 14 min
C. 16 min
D. 20 min
In this problem, rate of water pipe (waste) is more, the tank will be emptied when the pipes are opened.
Work done in total emptying in 1 min.
=1/16−1/32=1/32
Now, full tank will be emptied by them in 32 minutes.
Half full tank will be emptied in 16 minutes.