SSC GD 2023 PYQ — Question 50

SSC GD Constable (English) - 31 Jan 2023 - Shift 1 • Quantitative Aptitude • Q50

If the surface area of a sphere S1 is 800% greater than that of sphere S2, and the volume of sphere S2 is x% lower than sphere S1, then ‘x’ in terms of percentage is:

(Rounded off to two places of decimals.)

Show answer & explanation

Correct answer: C

Explanation

The correct answer is option 3 i.e. 96.29%

Given that

If the surface area of sphere S1 is 800% greater than that of sphere S2,

the volume of sphere S2  is x% lower than that of sphere S1

Formula used

Surface Area of Sphere = 4πr²

The volume of a sphere is V = 4/3 π r³

Calculation

4πr1² = 9 × 4πr2²

r1 = 3 r2

So, r13 = (10.39 r2)3 = 27 r23

r23/r13 = 1/27

Now, the % change in volume = [(27 - 1)/27] × 100 = 96.29%