If the radius of a hemisphere is increased by 50%, then find the percentage increase in the volume. (Take π = 22/7)

Explanation

Official answer key: (3) 125% Correct answer should be 237.5% (not in the options). Volume of a hemisphere = (2/3)πr³, so when r becomes 1.5r the volume becomes 1.5³ = 3.375 times, an increase of 237.5%. 125% is the increase in the curved surface area (1.5² = 2.25 times), not the volume. Scoring follows the official key.