How many more minutes would it take the driver to travel a distance of 10 miles at a speed of 45 miles per hour than at a speed of 50 miles per hour

45 miles per hour divided by 60 minutes is .75 miles a minute.10 miles divided by .75 is 13.33 minutes rounded to 13
50 miles per hour divided by 60 minutes is .83 miles per minute.10 miles divided by .83 is 12.04 minutes rounded to 12
13 - 12 = 1 more minutes

Divide 40%5 and your answer is 8