Time taken to fill the bathtub is 8 min time taken to drain the bathtub is 12 min fraction of bathtub filled in 1 hour=1/8 fraction of bathtub drained in 1 hour=1/12 fraction that will be filled in a minute given that both taps are opened at he same time: 1/8-1/12 =1/24 thus time taken for the bathtub to be filled is 24 min
