Example 1 · level 1
A square sheet of paper is folded along the dashed line, and holes are punched through every layer. Which figure shows the sheet when it is opened out?
- A
- B
- C
- D
Show solution
- Fold 1: along the horizontal centre line, top half down onto the bottom half.
- Punched: row 3, column 2 and row 3, column 1.
- Undo the folds from last to first, reflecting every hole in the crease each time. That gives 4 holes: row 3, column 2; row 3, column 1; row 2, column 2; row 2, column 1.
- Only figure (A) has exactly these holes.
Answer: A