Question

A pipe can fill a tank in 12 hours. By mistake a waste pipe at the bottom is left open and the tank is filled in 16 hours. If the tank is full how much time will the waste pipe take to empty it?

Answer 1

Portion of the tank emptied by the waste pipe in one hour
=1/12 - 1/16=1/48
Ans -48 hours

Answer 2

Answer:

The total time taken to empty it is 48 hours

Step-by-step explanation:

Given : A pipe can fill a tank in 12 hours. By mistake a waste pipe at the bottom is left open and the tank is filled in 16 hours.

To find : If the tank is full how much time will the waste pipe take to empty it?

Solution :

The pipe can fill a tank without any leak in 12 hrs.

Work done without leak in 1 hour is $\frac{1}{12}$

The waste pipe can fill a tank with leak in 16 hrs.

Work done with leak in 1 hour is $\frac{1}{16}$

Now,

Work done by leak in 1 hour is

$=\frac{1}{12}-\frac{1}{16}$

$=\frac{4-3}{48}$

$=\frac{1}{48}$

So, The total time taken to empty it is 48 hours.