Question

A faucet can fill a sink in 3 minutes. It takes 2 times as long for the drain to empty the sink. How long will it take to fill the sink if the drain is open and the faucet is on?

Answer 1

`6` minutes time will be required to fill the sink,when both
the faucet and drain are open.

Explanation:

Let the volume of sink is `v` . The sink is filled in `3` minutes.

Therefore In `1` minute `1/3` part of sink is filled up.

The sink is drained out to empty in `3*2=6` minutes.

Therefore In `1` minute `1/6` part of sink is emptied.

When both the faucet and drain is open the sink fills

`1/3-1/6 = 1/6` part in one minute. Therefore to fill

completely required time is `1/(1/6)=6` minutes ,when both

the faucet and drain is open [Ans]