Question

The diameter of a road roller is 60 cm and it is 140 cm long. It levelled an area of $79,200c{m}^2$. How many turns did the road roller take to level the said area?

Answer 1

A road roller is cylindrical in shape.

Radius, $r=\frac{60}{2}=30cm$

Height, $h=140cm$

Curved surface area of the roller

$=2\pi rh$

$=2\times \frac{22}{7}\times 30\times 140$

$=26,400c{m}^2$

In 1 turn, the roller will level $26,400c{m}^2$ area.

Hence, no. of turns it will take to level $79,200c{m}^2$ will be

$n=\frac{79,200}{26,400}=3$