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?

1 Answer
May 19, 2018

#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]