A man walks diagonally across a square instead of along two edges. Approximately what percentage distance is saved?
Aptitude
Area
Difficulty: Easy
Choose an option
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A25.0%
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B29.3%
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C33.3%
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D22.5%
Answer
Correct Answer: 29.3%
Explanation
Problem restatementCompare the diagonal path to the L-shaped edge path around one corner of a square and find the percentage saving in distance.
Given data
- Square side = a.
- Edge path distance = a + a = 2a.
- Diagonal distance = a√2.
Concept/ApproachPercent saved = [(edge path − diagonal) ÷ edge path] × 100%.
Step-by-Step calculationPercent saved = [(2a − a√2) ÷ 2a] × 100%= (1 − √2 ÷ 2) × 100% ≈ (1 − 0.7071) × 100%≈ 29.3%
Verification/AlternativeFor a = 1: edge = 2, diagonal ≈ 1.4142, saving ≈ 0.5858 ⇒ 0.5858 ÷ 2 ≈ 29.29%.
Common pitfallsUsing 1 − (1/√2) instead of 1 − (√2/2); both are equal numerically here, but ensure the reference distance is the edge path (2a).
Final Answer29.3%