Average speed = (distance covered) / (time to cover the distance)
= (20 miles) / (45 minutes)
Multiply that fraction by (60 minutes / 1 hour) .
This is equal to ' 1 ', so you won't change anything except the units.
= (20 miles / 45 minutes) times (60 minutes / 1 hour)
Multiply the fractions, then cancel 'minutes' out of
the numerator and denominator.
= (20 miles x 60) / (45 x 1 hour)
= (20 x 60 / 45) miles/hour
= 26-2/3 miles/hour .