Answer:
r = 70.59 miles / hour
Explanation:
Comment
The first set of numbers gives you the distance you travelled.
Givens
t = 20 minutes = 20/60 = 1/3 of an hour
r = 60 miles / hour
d = ?
d = r * t
d = 60 * 1/3
d = 20 miles (The hours cancel)
So now you can find out what 17 minutes means
d = 20 miles
t = 17 minutes = 17/60 hours = 0.2833 hours.
r = d / t
r = 20 / 0.2833
r = 70.59 miles / hour