2022 · Q69
A rectangular sheet is of length x and breadth y. If p is the volume of the cylinder formed by rolling the sheet along its breadth and q is the volume of the cylinder formed by rolling the sheet along its length, and q = 2p, then which one of the following is correct?
Elementary MathematicsMensuration
- Ax = y
- B2x = 3y
- Cx = 2y
- D3x = 4y
Explanation
Rolling so the breadth y is the circumference: p = π(y/2π)²x = xy²/4π; rolling so the length x is the circumference: q = x²y/4π. From q = 2p, x = 2y. The distractor swaps which side becomes the circumference. Hence the keyed option is C.