A car travels 60 miles in 50 minutes. Calculate the average speed of the car in mph.

Average speed: 72 mph
Explanation:
To get the car's average speed, all you really need to know is
the total distance travelled by the car
the total time it needed to cover that distance
In your case, you know that the car travelled for a total of 60 miles and that it needed 50 minutes to do so.
Since you need to express the average speed in miles per hour, not miles per minute, you're going to have to use a simple conversion factor to get you from minutes to hours.
First, calculate the average speed in miles per minute
v
avg
=
d
total
t
total
v
avg
=
60 miles
50 minutes
=
1.2 mi/min
Now convert this value to miles per hour
1.2 miles
1
minute
⋅
60
minutes
1 hour
=
72 mph