Question

The wheels on a car have a diameter of 28 inches. How many full revolutions will the wheels need to make to travel 200 feet?

Answer 1

Here we're interested in the circumference:  C = pi*d.  In this case C = 3.14*(28 inches) = 88 inches. 

Now divide this 88 inches into 200 feet to get the # of revolutions ncessary to travel 200 feet.

200 feet     12 in
------------ * --------- = 2400 inches
       1           1 ft

2400 inches
----------------------- = 27.2 revolutions   (answer)
[ 88 inches/ rev ]