SOLUTION: It takes 3 people to clean a pool in 4 hours. How many people do we need to clean 6 pools in 8 hours? It seems to be a triple proportion but how exactly would I set it up?

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Question 1165522: It takes 3 people to clean a pool in 4 hours. How many people do we need to clean 6 pools in 8 hours?
It seems to be a triple proportion but how exactly would I set it up?

Found 3 solutions by josgarithmetic, ikleyn, greenestamps:
Answer by josgarithmetic(39617)   (Show Source):
You can put this solution on YOUR website!

Rate for 1 worker, r
number of workers, n
rate for n workers, nr

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It takes 3 people to clean a pool in 4 hours. How many people do we need to clean 6 pools in 8 hours?
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---------------the job of cleaning ONE pool.

--------------the question

Divide the second equation by the first equation and solve for n.

Answer by ikleyn(52778)   (Show Source):
You can put this solution on YOUR website!
.

One job (to clean 1 pool) is 3*4 = 12 man-hours. 6 pools is 6 jobs, and they require 6*12 = 72 man-hours. The required number of people is = 9. ANSWER

Answer by greenestamps(13198)   (Show Source):
You can put this solution on YOUR website!

You have received two responses showing perfectly good ways to solve a problem like this.

There are many other ways; following is a solution by the method I find easiest to use.

Given: 3 people to clean 1 pool in 4 hours.

(1) The number of pools is increased from 1 to 6, a factor of 6. Keeping the time the same, that means 6 times as many people.

3*6 = 18

(2) The amount of time is doubled, from 4 hours to 8 hours. Keeping the number of pools the same, the number of people required is cut in half.

18(1/2) = 9

ANSWER: 9 people