Question

Each wheel of a car is of diameter 80 cm. How many completer revolutions does each wheel make in 10 minutes when the car is traveling at a speed of 66 km per hour?

Answer 1

The car travells in 10 minutes
= `66/6`   = 11 km  = 1100000 cm

Circumference of the wheel = distance covered by the wheel in one revolution 

Thus, we have,
Circumference = 2 x `22/7 xx 80/2` = 251.43 cm

Thus, the number of revolutions covered by the wheel in 1100000 cm = `[ 1100000]/[251.43]` ≈ 4375.