Question 81907
During rush hour, Fernando can drive 20 miles using the side roads in the same time that it takes to travel 15 miles on the freeway. If Fernando's rate on the side roads is 9 mi/h faster than his rate on the freeway, find his rate on the side roads.
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Side road DATA:
distance = 20 mi ; Rate = x+9 mph ; time = d/r = 20/(x+9) hrs.
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Freeway DATA:
distance = 15 mi ; Rate = x mph ; time = d/r = 15/x hrs.
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EQUATION:
time = time
20/(x+9) = 15/x
20x = 15x+135
5x = 135
x = 27 mph (rate on freeway)
x+9 = 36 mph (rate on side roads)
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Cheers,
Stan H.

A) 38 B) 36 C) 27 D) 29