The length of a rectangle is increased by 25% and its breadth is decreased by 20%. What is the effect on its area?
Correct answer: A. Remains same
- A. Remains same
- B. 5% decrease
- C. 5% increase
- D. 10% increase
Explanation
The new area factor is 1.25 x 0.80 = 1.00, so the area remains unchanged. Equivalently, the 25% increase is exactly offset by the 20% decrease applied to the enlarged length. Option a is correct; option c, 5% increase, comes from simply subtracting 20% from 25% without considering multiplication of the dimensions.
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Percentages express a quantity as parts per hundred and support calculations involving increases, decreases, discounts, commissions, taxes, and successive changes. Questions require distinguishing percentage change from percentage points and identifying the original value when a final value and its percentage change are given.
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