Homework Help

It took John 12 hours riding his bike to make the round trip to his uncle's. If he...

user profile pic

ivorywashere | eNotes Newbie

Posted June 24, 2013 at 2:51 PM via web

dislike 1 like
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.)

Tagged with algebra 2, literature, math

1 Answer | Add Yours

user profile pic

justaguide | College Teacher | (Level 2) Distinguished Educator

Posted June 24, 2013 at 2:58 PM (Answer #1)

dislike 2 like

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.

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes