Question 1
A sheet of paper is folded first horizontally (top to bottom), then vertically (left to right). A single hole is punched at the center of the final folded square. Determine the pattern when completely unfolded.
Comprehensive Multi-Fold Solution:
Step 1 - Understanding Double Folds:
- Sequence: first horizontally (top to bottom), then vertically (left to right)
- Creates: 4 layers total (2 × 2)
- Layer structure: Quartered paper with all quarters stacked
- Symmetry: Both horizontal and vertical axes
Step 2 - Layer-by-Layer Analysis:
- First fold (horizontal): 2 layers - top and bottom
- Second fold (vertical): Each of 2 layers folds to create 2 more → 4 total
- Final stack: All 4 quarters perfectly aligned
- Punch location: center of final folded square
Step 3 - Hole Multiplication Mathematics:
- Single punch through 4 layers = 4 holes when unfolded
- Pattern determined by fold symmetry
- Horizontal fold: creates vertical symmetry (y-axis reflection)
- Vertical fold: creates horizontal symmetry (x-axis reflection)
- Combined: creates both symmetries (quarter-turn symmetry)
Step 4 - Final Positions:
- Hole 1: (25,25) - top-left region
- Hole 2: (75,25) - top-right region
- Hole 3: (25,75) - bottom-left region
- Hole 4: (75,75) - bottom-right region
Step 5 - Pattern Recognition:
- Four holes form square pattern
- Centered around paper center
- Equal spacing from center
- Perfect quarter-turn symmetry
- Result: Four holes in a square pattern around the center
Advanced Insight: For n perpendicular folds, single punch creates 2^n holes in grid pattern.
Verification: Count confirms 2² = 4 holes for 2 folds.