If A and B are taps that fill a tank in 36 and 48 minute respectively. Both taps were to be opened, however after x minutes B was switched off. If the tank was completely filled 24 minutes after both taps were opened, then find x.
A fills 1/36 of the tank in one minute
B fills 1/48 of the tank in one minute
After 24 minutes tank A been opened the whole time and had filled (1/36) * 24 = 24/36 = 2/3 of the tank
So in x minutes, tank B must have filled the other 1/3 of the tank
(1/48) x = 1/3 mutiply both sides by 48
x = 48/ 3 = 16 minutes