The diameter of the front wheel of an engine is 2x cm and that of rear wheel is 2y cm to cover the same distance, find the number of times the rear wheel will revolve when the front wheel revolves 'n' times,

Answer: Option C

Circumference of front wheel × number of its revolutions = circumference of rear wheel × number of its revolutions
2πx × n = 2πy × m (let 'm' is the revolution of rear wheel)
$$m=\frac{nx}{y}$$