SOLUTION: 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 to the nearest tenth

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Question 395820: 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 to the nearest tenth)
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

D = r*t or D/r = t

Question states***total trip was 12hr

 D/20mph + D/30mph = 12hr |multiplying each term by 60mph so as all denominators=1

 3D + 2D = 12*60

     5D = 720

       D = 144mi, the amount traveled each way