UPSC 2016 CDS II Math Paper

Radius of the front wheel = x cm
Distance covered by the front wheel in n revolutions = n × 2πx cm
Radius of the rear wheel = y cm
Let the number of revolutions made by the rear wheel to cover the same distance be m.
Distance covered by the rear wheel in m revolutions
=m×2πy‌cm
∴m×2πy=n×2πx
⇒m=

nx

y