The radius of a sphere is increased by 50%. The increase in surface area of the sphere is :
100%
125%
150%
200%
Explanation:
Take radius 100. Then surface area is 4 × pp × 100 × 100.
After increase radius by 50% the radius becomes100 + 50% of 100 = 150
Then new surface area is 4 × $\pi^2$ × 150 × 150
Then put the values into formula of percentage = 4$\pi$1502 - 4$\pi$10024$\pi$1002 × 1004$\pi$1502 -4$\pi$10024$\pi$1002 × 100 = 125%