It took John 12 hours riding his bike to make the round trip to his uncle's. If he averaged 20 mph out and 30 mph back, how long did he travel each way? (Round answer to nearest tenth.)

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justaguide | College Teacher | (Level 2) Distinguished Educator

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John took 12 hours to make the round trip to his uncle. His average speed going was 20 mph and while coming back hos average speed was 30 mph.

Let the time taken while going equal T, the time taken to come back is 12 - T. As distance = speed*time

T*20 = (12-T)*30

=> 20T = 360 - 30T

=> 50T = 360

=> T = 7.2

John took 7.2 riding to his Uncle's and 4.8 hours coming back.

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