if he ran 7 1/2 miles and one lap is 1 1/2 miles then you need to add 1 1/2 miles up until you get the distance he ran which is 7 1/2 miles and when u keep adding 1 1/2 miles to get to 7 1/2 you get 5 laps. hope this helps :)
Why? Because with each lap stating to be one and a half miles; you first and only step is to divide, seeing how each time you put 1 1/2 into the value of this 7 1/2 miles, you got a lap each time.
