Question

The diametr of the wheel of a car is 77cm.How many revolution will it make to travel 121km

Answer 1

Let the number of revolutions be x.
x* Circumference of wheel= Area covered
x*2Πr=121 km
x*2*22/7*77/2=12100000cm
x*44*77/14=12100000
x*3388/14=12100000
x*242=12100000
x=50000
Hence, the wheel of the car has to take 50,000 revolutions to cover an area of 121 km.

Answer 2

To make 1 revolution it needs to travel distance equal to its circumference
Diameter​ = 77cm
Circumference = πd
= 22/7 * 77
= 22*11
= 242 cm

121 km = 12100000 cm

Revolutions = 12100000 / 242
= 50000

The car wheel needs to make 50000 revolutions to travel 121 km.