Question 101407
If you pay $80 to rent the car, then you have $320 left to pay for the miles you are going to drive. 
(That amount comes from $400 - $80 = $320).
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At 25 cents per mile, you can drive 4 miles for each dollar you spend on mileage. (That comes
from {{{1.00/0.25 = 4 }}} miles per dollar)
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And since you have 320 dollars to spend on mileage, at the rate of 4 miles per dollar you
can drive 320 * 4 = 1280 miles during the week.
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Hope this helps you to see how you can think your way through problems such as this rather
than trying to develop and equation that you plug numbers into.
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