# Mensuration-21

### From Homeworkwiki

**How many times will the wheel of a car rotate in a journey of 88 km if it is known that the diameter of the wheel is 56 cm ?**

**(Take pi = 22/7)**

**Solution:** Diameter of the wheel = 56 cm. Radius of the wheel = 28 cm

Therefore, Circumference of the wheel = 2 Π r = 2 x 22/7 x 28 = 176 cm

Length of the journey = = 88 km = 88 x 1000 x 100 cm

Number of times the wheel will rotate = (88 x 1000 x 100) / 176 = 50, 000