Answer:
It will take 4.4 hours to fill the swimming pool when two pumps are opened.
Explanation:
Given:
One pump can fill a swimming pool in 8 hours and another pump can fill it in 10 hours.
First we need to calculate, in 1 hour how much water a pump pour into the swimming pool.
In 1 hour, the first pump can pour water into the swimming pool =
![(1)/(8)](https://img.qammunity.org/2020/formulas/mathematics/college/oishxf3znbtm7sgua7hx3bnp2grk4mwmno.png)
In 1 hour, the second pump can pour water into the swimming pool =
![(1)/(10)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/f0kl3hva794obvksa4xz9t90l7g4syjgce.png)
Let "t" be the time taken to fill the pool when two both the pups are opened.
![(1)/(8) + (1)/(10) = (1)/(t)](https://img.qammunity.org/2020/formulas/mathematics/high-school/bj90d67d2xfn0h9d8l7afcko5bu6xzm41m.png)
Now we have to solve for t. We have to take LCD of 8 and 10.
The Least common denominator (LCD) of 8 and 10 is 40.
![(5)/(40) + (4)/(40) = (1)/(t)](https://img.qammunity.org/2020/formulas/mathematics/high-school/6qupgigndyz3vafbjgep3mdg7qpve6ozke.png)
![(5 + 4)/(40) = (1)/(t)](https://img.qammunity.org/2020/formulas/mathematics/high-school/8bkem5knzv7i9wthglauzb4d3bvtdy7lu1.png)
![(9)/(40) = (1)/(t)](https://img.qammunity.org/2020/formulas/mathematics/high-school/sj2ctyak2y2t6fo19joqgsnmedekzk5ac0.png)
Now we have to cross multiply and solve for t
9t = 40
Dividing both sides by 9, we get
t = 4.444
Which is approximately, t = 4.4 hours.
Therefore, it will take 4.4 hours to fill the swimming pool when two pumps are opened.