Question

The volume of a cylinder having a base radius of 3 cm is 396 cm³. Find its curved surface area (in cm²). (Use $\pi = \frac{22}{7}$).

• A. 280
• B. 264
• C. 301.5
• D. 320.6

Answer 1

The Correct Option is B

The volume of a cylinder is given by \(V = \pi r^2 h\), where \(r\) is the radius and \(h\) is the height. 

We are given \(V = 396\) cm³ and \(r = 3\) cm, and \(\pi = \frac{22}{7}\).

So, \(396 = \frac{22}{7} \times 3^2 \times h = \frac{22}{7} \times 9 \times h\).

\(h = \frac{396 \times 7}{22 \times 9} = \frac{396 \times 7}{198} = 2 \times 7 = 14\) cm.

The curved surface area of a cylinder is given by \(CSA = 2 \pi r h = 2 \times \frac{22}{7} \times 3 \times 14\).

\(CSA = 2 \times 22 \times 3 \times 2 = 264\) cm²