Question

A road roller takes 750 complete revolutions to move once over to level a road. Find the area of the road if the diameter of a road roller is 84 cm and length is 1 m.

Answer 1

In one revolution, the roller will cover an area equal to its lateral surface area.
Thus, in 1 revolution, area of the road covered = $2\pi rh$
$=2\times \frac{22}{7}\times42$ cm $\times1$m

$=2\times \frac{22}{7}\times\frac{42}{100}$ m x1m

$=\frac{264}{100}$ m2

In 750 revolutions, area of the road covered
$=(\frac{264}{100}×750)$m2
$= 1980$ m2