Thomas R. answered • 05/09/18

Tutor

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A.S. in math with a minor in physics

Whenever you do a problem and it keeps the same ratio but scales it up, that calls for a proportion:

(10 min) / (25 square feet) = (X min) / (300 square feet)

Cross-multiply to solve, as we always do with proportions:

10 * 300 = 25 * x

3000 = 25X

3000/25 = 25X /25

120 = X

Remember -- this time is in minutes, NOT the hours they requested! We have to adjust for that!

120 minutes * (1 hour / 60 minutes) = 2 hours