Question

The radius of a sphere is increased by 25% find the
percentage increased in csa

Answer 1

56.25% if radius becomes 25% more then, itwill 1.25 times of before. csa of sphere is directly square of radius . so increase in CSA is (1.25)^2 -1 = .5625 . and % is 56.25% I wish you will understand .

Answer 2

Answer:

56.25%

Step-by-step explanation:

Let the old radius be R & new radius = R'

New radius = R + R(25/100) = 5R/4

Let the old surface area = 4πR²

Now , New surface area = 4π(5R/4)²

= 25πR²/4

Increase in S.A = 25πR²/4 - 4πR²

= πR²(25-16)/4

= (9/4)πR²

Percentage increase=[(9/4)πR²/4πR²]100

= (9/16)*100

= 56.25 %