Question

Each week, Rosario drives to an ice skating rink that is 60 miles away. The round-trip takes 2.75 hours. If he averages 55 miles per hour on his way to the rink, which equation can be used to find x, the number of miles per hour he averages on his way home?

Answer 1

We have to use physics: vm = d/t
Where vm = average velocity
d = distance that one travel
t = time in which you travel

Using this formula we know that t = d/vm

First, we find how much time does it take to the rink:
t = 120/55

After we find out the time we have left:
2.75-120/55

Using the same formula we can now calculate the average on his way home =
120/(2.75-120/55)

The final equation:
x= 120/(2.75-120/55) = 211,2 miles per hour

Answer 2

He averages 36.14 miles per hour on his way home

Explanation:

Given:

Rosario drives to an ice skating rink that is 60 miles round-trip takes 2.75 hours. If he averages 55 miles per hour on his way to the rink

To Find: Find out the number of miles per hour he averages on his way home

Solution:

Total time taken for the trip = 2.75 hours

FIRST CASE : Rosario on his way to the rink

distance traveled to ice skating rink = 60 miles

average miles per hour on his way to the rink = 55 miles per hour

So, time taken on his way to rink =
`(Distance)/(Speed) =(60)/(55)`

SECOND CASE: Rosario on his way to the home

Distance traveled to the home = 60 miles

Let Average miles per hour on his way to the home = x

So, time taken on his way to the home =
`(Distance)/(Speed) =(60)/(x)`

Since the total time was 2.75 hours

⇒
`2.75=(60)/(55) +(60)/(x)`

⇒
`2.75=1.09+(60)/(x)`

⇒
`1.66=(60)/(x)`

⇒
`x=(60)/(1.66)`

⇒
`x=36.14`

Thus , He averages 36.14 miles per hour on his way home