SSC MTS 2024 PYQ — Question 7

SSC MTS - 16/10/2024 - (9:00 AM - 11:00 AM) • Quantitative Aptitude • Q7

A solid cone of base diameter 20 cm and height 20 cm is melted and recast into a solid metal hemisphere of radius R cm. What is the total surface area(in cm², rounded off to 2 decimal places) of the hemisphere? (Take $\pi = \frac{22}{7}$ )

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 942.86.

Given, $\frac{1}{3} \pi r^2 h = \frac{2}{3} \pi R^3$

⇒ 10 × 10 × 20 = 2R³

⇒ R = 10 cm

TSA of hemisphere = $3\pi R^2$

⇒ 3 × (22/7) × 10 × 10 = 942.86