Question

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.)

Answer 1

Explanation:

Let the time taken by the john to get to his uncle be x.

Let the time taken by the john to get back from his uncle be y.

So,

x+y=12 ------ equation 1

According to the given velocities:

20x=30y

x=3/2y

Put the value x=3/2y in equation 1

3/2y+y =12

3y+2y/2=12

3y+2y=12*2

5y=24

y=24/5

y=4.8h

Now put the value of y in x=3/2y

x=3/2*4.8

x=14.4/2

x=7.2h ....