Question 269634
a motorist drove 150 miles on country roads before driving 50 miles on mountain roads. 
the rate of speed on the country roads was 3 times the rate on mountain roads.
the time spent traveling the 200 miles was 5 hours. 
find the rate of the motorist on country roads?
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Country Road DATA:
distance = 150 miles ; rate = 3x mph ; time = d/r = 150/(3x) = 50/x hrs.
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Mountain Road DATA:
distance = 50 miles ; rate = x mph ; time = d/r = 50/x hrs
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Equation:
time + time = 5 hrs
2(50/x) = 5
100/x = 5
5x = 100
x = 20 mph on mountain Roads
3x = 60 mph on country Roads
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Cheers,
Stan H.
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i let x=rate of the motorist on mountain road
and 3x rate of the motirist on country roads 
i set up the equation x/200 - 3x/200 = 5 
Comment: x/200 is time/distance = rate
But 5 is time
You need an equation that says time + time = time.