A rectangular paper of 20 cm × 8 cm is folded 3 times. Each fold is made along…

2024

A rectangular paper of 20 cm × 8 cm is folded 3 times. Each fold is made along the line of symmetry, which is perpendicular to its long edge. The perimeter of the final folded sheet (in cm) is

  1. A.

    18    

  2. B.

    24

  3. C.

    20

  4. D.

    21

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Correct answer: A

Reasoning: follow the size changes after each fold.

  • Start with 20 cm × 8 cm (long edge = 20). Each fold along the midline perpendicular to the current long edge halves that long edge.

  • After 1st fold: 20 → 10, sheet is 10 × 8 (long edge = 10).

  • After 2nd fold: 10 → 5, sheet is 5 × 8 (now long edge = 8).

  • After 3rd fold: halve the current long edge 8 → 4, sheet is 5 × 4.

  • Perimeter = 2 × (5 + 4) = 18 cm.

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