SOLUTION: A car travels 400 miles on level terrain in the same amount of time it travels 160 miles on mountainous terrain. If the rate of the car is 30 miles per hour less in the mountains t
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Question 221283: A car travels 400 miles on level terrain in the same amount of time it travels 160 miles on mountainous terrain. If the rate of the car is 30 miles per hour less in the mountains than on level ground, find its rate in the mountains. Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A car travels 400 miles on level terrain in the same amount of time it travels 160 miles on mountainous terrain. If the rate of the car is 30 miles per hour less in the mountains than on level ground, find its rate in the mountains.
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Mountain DATA:
distance=160 miles; rate = x-30 mph ; time = d/r = 160/(x-30) hr.
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Level DATA:
distance = 400 miles ; rate = x mph ; time = d/r = 400/x hr.
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Equation:
time = time
160/(x-30) = 400/x
160x = 400(x-30)
160x = 400x - 12000
-240x = -12000
x = 50 mph (level rate)
x-30 = 20 mph (mountain rate)
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Cheers,
Stan H.
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