SSC Selection Post 2024 PYQ — Question 61

SSC Selection Post - Higher Secondary Level - 25 June 2024 - Shift 4 • Quantitative Aptitude • Q61

A sphere and a cube have equal surface areas. The ratio of the volume of the sphere to that of the cube is:

Show answer & explanation

Correct answer: A

Explanation

The correct answer is Option 1 i.e. 6:π{{\sqrt6:}}{{\sqrtπ}}.

The surface area of cube = 6 a2

The surface area of sphere = 4π r2

Volume of a cube = a3

Volume of sphere = 4π r3/3

6a2 = 4 π r2

⇒ a2 = 4π r2/6

⇒ a2/r2 = 4π /6

⇒ a/r = 2 √π /√6 

Assuming, a = 2√π , r = √6

Volume of a cube = (2 √π)3

⇒  8π√π 

Volume of sphere = 4 π × (√6)3/3  

⇒ 4π × 6 √ 6/3 = 4 π × 2 √6

⇒ 8π √6  

The ratio of the volume of sphere and cube = 8π √6 ÷  8π √π

⇒ √6/√π