THE RADIUS OF A CIRCLE IS INCREASED BY 50. BY WHAT %WILL ITS AREA BE INCREASED?

Solution (By Examveda Team)

Let initial radius was 100.

Area = pi * R *R = 3.14 * 100 *100 = 31,400 sq. unit.

Ne radius = 100 + 50% of 100 = 150

New Area = pi * R *R = 3.14 * 150 *150 = 70650

Increased Area = 70650 - 31400 = 39,250

% Increased Area = (39250 *100)/31400 = 125%.

Short-cut

Let Initial area = 100.

100 === 50% (first radius increase) == 150 ===50% (second radius increase) ===> 225.

So, increase Area = 125%.