SSC Selection Post 2025 PYQ — Question 40

SSC Selection Post - Graduation Level - 29th July 2025 - Shift 3 • Quantitative Aptitude • Q40

A solid hemisphere is melted into a smaller hemisphere and a sphere of equal radii. If the smaller hemisphere’s radius is r, find the radius R of the original hemisphere.

Show answer & explanation

Correct answer: A

Explanation

Volume of the original hemisphere = Volume of the new hemisphere + Volume of the new sphere

(2/3)πR³ = (2/3)πr³ + (4/3)πr³

(2/3)πR³ = 2πr³

R³ = 3r³

R = ∛3 × r