Question

A tap takes 3 hours to fill a tank. A discharge tap takes 6 hours to empty the same tank. How long will it take to fill the tank with both taps open?

Answer 1

2 hours

Explanation:

first tap= 3hours

therefore work done is = 1/3

second tap= 6hours

therefore work done = 1/6

so, 1/3+ 1/6

=2/6 + 1/6

=3/6

=1/2

=2/1 hours

=2 hours