If the surface area of a sphere increased by 44%, find the percentage increase in diameter
A. 44 B. 30 C. 22 D. 20
Correct Answer: D
Explanation
Surface Area of Sphere A = 4\(\pi r^2\) ∴ A = 4\(\pi\)\(\frac{(D)^2}{2}\) = \(\frac{(D)^2}{2}\) = \(\pi\)D2 When increased by 44% A = \(\frac{144 \pi D^2}{100}\) \(\pi\)\(\frac{(12D)^2}{10}\) = \(\pi\)\(\frac{(6D)^2}{5}\) Increase in diameter = \(\frac{6D}{5}\) - D = \(\frac{1}{5}\)D Percentage increase = \(\frac{1}{5}\) x \(\frac{1}{100}\)% = 20%