SOLUTION: a trucker drove for 4 hours before he encountered icy road condition. He reduced his speed by 20 mph and continued driving for 3 more hours. Find his average speed during the fir

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Question 266340: a trucker drove for 4 hours before he encountered icy road condition. He reduced his speed by 20 mph and continued driving for 3 more hours. Find his average speed during the first part of the trip if the entire trip was 325 miles.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
a trucker drove for 4 hours before he encountered icy road condition. He reduced his speed by 20 mph and continued driving for 3 more hours. Find his average speed during the first part of the trip if the entire trip was 325 miles.
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1st segment DATA:
time = 4 hrs. ; rate = x mph ; distance = rt = 4x miles
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2nd segment DATA:
time = 3 hrs. ; rate = x-20 mph ; distance = rt = 3x-60 miles
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Equation:
distance + distance = 325 miles
4x + 3x-60 = 325 miles
7x = 385
x = 55 mph (rate during 1st segment)
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Cheers,
Stan H.