Question

One pump fills a tank two times as fast as another pump. If the pumps work together they fill the tank in 18 minutes. How long does it take each pump working alone to fill the tank?

Answer 1

Answer:

27 minutes by slower pump and 54 minutes by faster pump.

Explanation:

Let the faster pump can fill the tank in x minute.

The slower pump can fill the tank in 2x minutes.

Both fill the tank in 18 minutes.

In one minute faster pump will fill the tank,$\frac{1}{x}$

In one minute slower pump will fill the tank,$\frac{1}{2x}$

In one minute both pump will fill the tank,$\frac{1}{18}$

According to question,

$\frac{1}{x}+\frac{1}{2x}=\frac{1}{18}\\\frac{3x}{2x^{2} }=\frac{1}{18}\\\frac{2x^{2}}{3x}=18\\x=27$

Tank filled by faster pump will be, $2x=2\times 27=54 minutes$

Therefore, the tank filled by slower pump in 27 minutes and by the faster pump in 54 minutes.