SSC CGL 2026 PYQ — Question 5

SSC CGL Tier II - 19 Jan 2026 - Shift 1 • Quantitative Aptitude • Q5

A hemispherical tank is full of water. It is connected to a pipe that empties it at a rate of 7 litres per second. How much approximate time (in minutes) will it take to empty half the tank if the internal radius of the tank is 2.1 meters? (Use $\pi = \frac{22}{7}$ and 1 m³ = 1000 liters).

Show answer & explanation

Correct answer: D

Explanation

The correct answer is Option 4 i.e. 23 minutes.

Hemisphere radius = 2.1 m

Volume of full hemisphere $= \frac{2}{3} \pi r^3 = \frac{2}{3} \times \frac{22}{7} \times (2.1)^3$

= 19.404 m³

= 19404 liters

Half tank volume = 19404/2 = 9702 liters

Time required = 9702/7 = 1386 seconds ≈ 23 minutes