Question 644568
Sarah and John are driving in opposite direction on a straight road. John is driving fifteen miles per hour faster than Sarah. After three hours they are 375 miles apart. How fast were Sarah and John traveling?
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You want to solve for "rate".
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Sarah DATA:
rate = x mph ; time = 3 hours ; distance = 3x miles
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John DATA:
rate = x+15 mph ; time = 3 hours ; distance = 3(x+15) miles
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Equation:
distance + distance = 375 miles
3x + 3(x+15) = 375
3x + 3x + 45 = 375
6x = 330
x = 55 mph (Sarah's rate)
x+15 = 70 mph (John's rate)
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Cheers,
Stan H.
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