Question

A cylindrical road roller length 2m and diameter 84cm .find the number of revolution it has to make to cover an area of 7920m

Answer 1

radius of roller = 42cm
length/height =200 cm
area covered in one revolution is
$\pi$
r h *2
$22 \div 7 \ \times 42 \times 200 \times 2$
equals to 52800cm square
or 528m square
no. of revolution equals it 7920/528
= 15