# How Much Time Taken By Them to Fill The Tank ? If

Answered

A pipe can fill a tank in x hours and another can empty it in y hours. They can together fill it in (y>x)

- xy
- y – x
- xy/(y – x)
- x – y

Best answer

**Answer: (3) xy/(y – x)**

**Explanation: –**

A pipe can fill a tank in = x hours

A pipe can fill a tank in a hour = 1/ x

Another pipe can empty it = y hours

Another can empty in a hour = 1 / y

They can together fill it in a hour = 1/x – 1/y

= (y – x)/xy

Therefore, They can fill it = xy / (x – y)

Hence, the answer is (3) xy / (y – x).