Question

Tap A can fill a tank in 9 hours and tap B can fill it in 6 hours. How long will it take to fill the tank, if both taps are opened together?

Answer 1

Tap A fills the tank in 3 hours

Thus it can fill 1/3 of the tank in 1 hour,

Tap B fills the tank in 6 hours.

This it can fill 1/6 of the tank in 1 hour

In how much time will the tank be filled if both the taps are opened together?

If both the tap opened together they can fill the tank

1/3 + 1/6

= (2 + 1)/6 in one hour

= 3/6 or 1/2 of the tank in one hour

Thus, in 2 hours both the tap can completely fill the tank.