Question

One pump can fill a swimming pool in 8 hours and another pump can fill it in 10 hours. If both pumps are opened at the same time, how many hours will it take to fill the pool?

Answer 1

Answer: It will take $\dfrac{40}{9}=4\dfrac{4}{9}$ hours to fill the pool.

Step-by-step explanation:

Since we have given that

Number of hours first pump takes = 8 hours

Number of hours second pump takes = 10 hours

If both pumps are opened at the same time,

Work done by first pump = $\dfrac{1}{8}$

Work done by second pump = $\dfrac{1}{10}$

According to question,we get that

$\dfrac{1}{8}+\dfrac{1}{10}\\\\=\dfrac{5+4}{40}\\\\=\dfrac{9}{40}$

So, it will take $\dfrac{40}{9}=4\dfrac{4}{9}$ hours to fill the pool.