SSC CPO 2023 PYQ — Question 145

SSC CPO - 05 Oct 2023 - Shift 2 • Quantitative Aptitude • Q145

A sphere and another solid hemisphere have the same surface area. The ratio of their volumes is:

Show answer & explanation

Correct answer: C

Explanation

The correct answer is option 3 i.e. 33\sqrt{3} : 4.

Given that

A sphere and another solid hemisphere have the same surface area

Volume of a sphere V = 4/3 π R³

Volume of a solid hemisphere = 2/3 π r³

According to the question

Surface area of a sphere = Surface area of a hemisphere

4π R2 = 3π r2

R/r = 3\sqrt{3}/2

Volume of a sphere/Volume of a solid hemisphere = (4/3 π R³)/(2/3 π r³)

= 2(R/r)3 

= 2(3\sqrt{3}/2)3 

= 33\sqrt{3} /4

Hence, The ratio of their volumes is 33\sqrt{3} : 4