Question

The radius of the base of a cylindrical tank is 4 m. If three times the sum of the areas of its two circular faces is twice the area of its curved surface, then the capacity (in kilolitres) of the tank is:

• A. 54 π
• B. 96 π
• C. 144 π
• D. 108 π

Answer 1

Answer:

B. 96 π

Area of circle = πr² Curved surface area of cylinder = 2πrh Volume of the cylinder = πr²h Three times the sum of the areas of its two circular faces is twice the area of its curved surface 3 × (2πr²) = 2 × 2πrh 6πr² = 4πrh (6 × π × 4 × 4) = (4 × π × 4 × h) h = 6 The capacity of the tank = πr²h = (π × 4 × 4 × 6) = 96π