Question

Liang is ordering new tires for his car. The tires he has have a circumference of 28π inches and a wheel rim with a circumference of 18π inches. How much larger is the radius of the tire than the radius of the wheel?

10 inches
5 inches
20 inches

Answer 1

5 inches

Explanation:

circumference = pi ×diameter

radius = half diameter

therefore radius = circumference / pi / 2

radius of tire = 28/2 = 14

radius of rim = 18/2 = 9

difference = 14-9= 5 inches