What is the speed of a boat in miles per hour that travels 20 miles in 45 minutes?

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 .  

Go to the bathroom and vape