SOLUTION: Rachel and Monica are working on printing résumés. Rachel and Monica working together can finish printing the résumés in 3.5 hours. Rachel working by herself is 4 times as slow

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Question 1196844: Rachel and Monica are working on printing résumés. Rachel and Monica working together can finish printing the résumés in 3.5 hours. Rachel working by herself is 4 times as slow as Monica. How long will Rachel take to finish printing the résumés by herself?
Found 2 solutions by greenestamps, Alan3354:
Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


"4 times as slow" is common (but sloppy) everyday English; but it is poor mathematical form....

I will assume it means that it takes Rachel 4 times as long as Monica to do the work.

That means when working together Rachel does 1/4 as much work as Monica; and that means she does 1/5 of the work. (If you don't see that right away, look at it like this: Rachel does 1/5 of the work; Monica does 4 times as much work, which is 4/5 of the work; together they do 1/5 of the work plus 4/5 of the work, which is the whole job.)

So in 3.5 hours Rachel does 1/5 of the work; that means the amount of time it would take her to do the job alone is 5*3.5 = 17.5 hours.

ANSWER: 17.5 hours


Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
"4 times as slow" is meaningless.
1 time as slow would be zero.
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Same for "10 times smaller" and "10 times closer."