2021 · Q39
A rectangular paper is 44 cm long and 22 cm wide. Let x be the volume of the largest cylinder formed by rolling the paper along its length and y be the volume of the largest cylinder formed by rolling the paper along its width. What is the ratio of x to y? (Take π = 22/7)
Elementary MathematicsMensuration
- A1 ∶ 1
- B2 ∶ 1
- C1 ∶ 2
- D3 ∶ 2
Explanation
Rolled along its length: circumference 44 gives r = 7, height 22, so x = π·49·22. Rolled along its width: circumference 22 gives r = 3.5, height 44, so y = π·12.25·44. The ratio x/y = (49·22)/(12.25·44) = 2, i.e. 2 : 1. Hence option B.