2017 · Q76
Two rectangular sheets of sizes 2π x 4π and π x 5π are available. A hollow right circular cylinder can be formed by joining a pair of parallel sides of any sheet. What is the maximum possible volume of the circular cylinder that can be formed this way ?
Elementary MathematicsMensuration
- A4 π²
- B8 π²
- C1.25 π²
- D6.25 π²
Explanation
Joining the longer side as circumference: sheet 2π×4π gives r = 2, h = 2π, V = 8π²; sheet π×5π gives r = 2.5, h = π, V = 6.25π². Using the shorter sides as circumference gives 4π² and 1.25π². The maximum is 8π². Hence option (B) 8π².