Question

There are two pipes in a tank. pipe a is for filling the tank and pipe b is for emptying the tank. if a can fill the tank on 10 hours and b can empty the tank in 15 hours then find how many hours will it take to completely fill a half empty tank?

Answer 1

will completely filled and half in 25 hours

Answer 2

Answer:

Time taken to completely fill a half empty tank is 15 hours

Step-by-step explanation:

Given,

A can fill a tank in 10 hours

B can empty a tank in 15 hours

Part of tank filled by A in 1 hour = $\frac{1}{10}$

Part of tank emptied by B in 1 hour = $\frac{1}{15}$

Net part of tank filled in 1 hour = $\frac{1}{10}$ - $\frac{1}{15}$

= $\frac{15-10}{150}$

= $\frac{5}{150}$

= $\frac{1}{30}$

Therefore,

Both a and b can fill tank in 30 hrs

According to question,

Tank should be half empty

So time taken to fill the half tank =  $\frac{30}{2}$ = 15

Thus , Time taken to completely fill a half empty tank is 15 hours