Question

A water fountain is in circular shaped whose radius is 10 m. Its inner portion of radius 3m is arranged for fountain and remaining part is cemented. Find the area of that cemented part and total cost of cementing if cost of cementing is ₹ 200 per sq.m.

Answer 1

Radius for total water fountain (R) = 10m 

Radius of fountain arranged portion (r) = 3 m 

Area of cemented part = Area of total water fountain – Area of fountain arranged portion

= πR² – πr²

= 22 × 13

Given the cost of cementing per sq.m = ₹ 200 

∴ Total cost of cementing = 286 × 200 = ₹ 57,200