Question

A tap p can empty the tank in 12 minutes alone and in 8 minutes along with tap q

Answer 1

Tap empties in 12 minutes.

In one minute the amount emptied is :

1/12

Let the time taken by q be :

x.

In one minute the amount emptied is :

1/x

They both empty the tank in 8 minutes so in one minute they empty :

1/8

So in one minute we have :

1/12 + 1/x = 1/8

1/x = 1/8 - 1/12

1/x = 1/24

So x = 24 minutes

So tap q takes 24 minutes to empty the tank.