Math CentralQuandaries & Queries


Question from Lee:

here are two word problems i've been doing but can't get the hang of:
1) a student saved $50.25 in one month. at that rate how long will it take
the student to save $700?

2) for summer job, martin shampooed rugs. he could finish a 4mx 4m rug in 30 min.
his supervisor could finish a similar:smaller rug in 20 min. how long would
it take for them to finish the rug if they worked together?


Hints for 1): you are not meant to worry about interest rates. The question is just, if one month represents $50.25 saved,how many times must this be done to get to $700? The answer will not be a whole number of months.

2) Usually problems like this involve people working at different speeds. If this is the case here, we do not have enough information to solve the question (which I consider to be rather badly written!)

We cannot assume the rugs to be the same size, as one is said to be smaller. So our only natural simplifying assumption is that both cleaners work at the same speed.

IF you make this assumption the problem is easy.

Good Hunting!

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