Question

The outer circumference of a circular race track is 528m. The track is everywhere 14m wide. Calculate the cost of leveling the track at rate of 50 paise per square metre.

Answer 1

Let inner radius = r width(d) = 14m

Outer radius = R

Outer circumference of track = 2πr

∴ 2πr = 528

Inner radius r = R – d = 84 – 14 = 70m

Area of track = (area of outer circle) – (area of inner circles)

Total cost of leveling track = 6776 x 1/2=Rs.3388