Question

An athlete runs around a circular track. The track has a diameter of 200 feet. How many laps does she need to take to run a mile?

Answer 1

First you have to figure out the length of the track:

$2 * \pi * r$

r is the half of the diameter:
200ft : 2 = 100ft

$2* \pi *100ft$ = 200$\pi$≈ 628,31

The athlete has to run ca. 5280ft for one mile:

5280 : 628,31≈8,4

The athlete has to run 8,4 laps