SSC JE Mechanical Engineering 2018 Set 4 Paper

The power transmission takes place from a pulley of diameter 1 m running at the speed of 250 rpm to a pulley of 2.50 m diameter by means of a belt.
Determine the speed (in rpm) of the driven pulley?
$\frac{{\mathit{N}}_2}{{\mathit{N}}_1}=\frac{{\mathit{D}}_1}{{\mathit{D}}_2}$
$\frac{250}{{\mathit{N}}_1}=\frac{2.5}{1}$
${\mathit{N}}_1=100$rpm.