Question

Two taps a and b can fill a tank in 48 minutes and 36 minutes if both are opened together after how much time is closed

Answer 1

part of work done by both taps 1/48 + 1/36= 7/144
then time taken is 144/7 =20.55 minutes

Answer 2

The complete question is:

Two taps a and b can fill a tank in 48 minutes and 36 minutes if both are opened together after how much time Tap A is closed so that the whole tank will fill in 25min 30 sec.

Given:

(i) Two taps a and b can fill a tank in 48 minutes and 36 minutes.

To find:

(i) How much time time will be required after Tap A is closed so that he time required so that the whole tank will fill in 25min 30 sec.

Solution:

First, let us calculate the capacity of tank.

Let us take the capacity of the tank to be the LCM of 48 and 36= 288L

Tap A's rate of filling = 288/48 = 6L/min

Tap B's rate of filling = 288/36 = 8L/min

Since B is open for 25min 30sec,

Water filled = (25.5*8) L

= 204L

Water filled by A = 288-204 L

= 84L

Time for which it was open = 84/6 = 14min

So, 14 minutes is the required answer.