Question

The diameter of a roller is 84 cm and its length is 120 cm. It takes 500 complete revolutions to move once over to level a playground. Find the area of the playground in $m^2$? $[Assume\pi =\frac{22}{7}]$

• A. $1984m^2$
• B. $1584m^2$
• C. $2584m^2$
• D. $1534m^2$

Answer 1

The correct option is B

$1584m^2$

A roller is cylindrical shaped.
Height (h) of cylindrical roller = Length of roller = 120 cm
Radius (r) of the circular end of roller $=\left(\frac{84}{2}\right)cm=42cm$
CSA of roller $=2\pi rh$
$=31680c{m}^2$
Area of field $=500\times CSA$ of roller
$=(500\times 31680)c{m}^2=15840000c{m}^2=1584m^2$