The GATE Grind

GATE 2021 CH – Question 4

General Aptitude · Spatial Aptitude: Spatial Reasoning and Visualization · 1 mark · Multiple choice

A circular sheet of paper is folded along the lines in the directions shown. The paper, after being punched in the final folded state as shown and unfolded in the reverse order of folding, will look like

a circle is folded into a semicircle and then a quarter-circle, with punches at the centre and along both folded edges; the four possible unfolded patterns are shown.
  1. Option A in the figure
  2. Option B in the figure
  3. Option C in the figure
  4. Option D in the figure

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Show answer and explanation

Correct answer: (B) Option B in the figure

Explanation

Undo the last fold by reflecting each cut about the horizontal diameter; then undo the first fold by reflecting the resulting cuts about the vertical diameter. The quarter-circle cut at the intersection of the folds becomes one central circular hole.

The long slit meeting the vertical fold becomes a long horizontal slit above the centre, with its mirror below. The small slit meeting the horizontal fold becomes a short horizontal slit on each side. This is the pattern in **B**; A makes the side slits vertical, while C and D orient the long slits incorrectly.