SOLUTION: One morning, Justin drove 2 hours before stopping to eat lunch at Pizza Hut. After lunch, he increased his speed by 10 mph. If he completed a 470-mile trip in 7 hours of driving ti
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Question 706985: One morning, Justin drove 2 hours before stopping to eat lunch at Pizza Hut. After lunch, he increased his speed by 10 mph. If he completed a 470-mile trip in 7 hours of driving time, how fast did he drive in the morning? Answer by nshah11(47) (Show Source):
You can put this solution on YOUR website! Assume Justin's speed in the morning was x mph. It then follows from the problem that:
(470 - 2x)/(x + 10) = 5
470 - 2x = 5x + 50
420 = 7x => x = 60 mph
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