Rectangle sides each increased by 20%: By what percentage does the area of the rectangle increase?
Aptitude
Area
Difficulty: Easy
Choose an option
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A22%
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B33%
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C44%
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D55%
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ENone of these
Answer
Correct Answer: 44%
Explanation
Introduction / Context:Area of a rectangle scales with the product of its sides. Increasing both sides by the same percentage leads to a compounded (quadratic) increase in area.
Given Data / Assumptions:Sides become 1.2 times original.
Concept / Approach:New area factor = 1.2*1.2 = 1.44; percentage increase = (1.44 − 1) * 100% = 44%.
Step-by-Step Solution:
Let sides be a, b → area = ab.New sides = 1.2a, 1.2b.New area = 1.44ab ⇒ increase = 44%.Verification / Alternative check:Choose numbers (10 by 10 → 100; new 12 by 12 → 144; +44%).
Why Other Options Are Wrong:22%, 33%, 55% are linear/partial misreads; exact value is 44%.
Common Pitfalls:Adding 20% + 20% = 40% (ignores compounding); correct is 44%.
Final Answer:44%