Question

Three pumps can remove a total of 1700 gallons of water per minute from a flooded mineshaft. If engineers want to remove at least 5500 gallons per minute, how many pumps will they need operating?

Answer 1

`color(blue)(10)` water pumps

Explanation:

First, write an equation and solve to find how many gallons of water per minute each pump removes:
`1700 = 3 * G`
G stands for the gallons of water that one pump can remove per minute.
`G = 566.bar66 ~~ 566.67` gallons per minute

Then, write an equation and solve to find how many pumps are needed to remove at least 5500 gallons per minute:
`5500 = P * G`
G = gallons of water per minute per pump
P = number of pumps
`5500 <= 566.67P`
`9.706 = P ~~ 9.71`

Since 9.71 pumps would pump 5500 gallons per minute, and you cannot have a fraction of a pump. round up to 10 pumps.

Finally, check your answer:
`5500 <= 566.67*10`
`5500 <= 5666.7`