The tyre of a car wheel has an outer diameter of 30 cm. How many times will the wheel rotate on a journey of 5km.

Question

This is a nice question to ask, try your best to find it.

Answer 1

The diameter is 30 cm, therefore the radius is 15 cm.  The circumference of the tire is found by using the formula C = 2πr.  C ≈ 2(3.14)(15) ≈ 94.2 cm. 5 km = 500,000 cm (5 x 1000 x 100).  500,000 ÷ 94.2 ≈ 5307.86 or about 5300 times (revolutions).  (using π, instead of 3.14, I got 5305.16 revolutions)