Question
The ratio of length to breadth of a rectangle is 8:5. When the length and breadth of the rectangle is increased by 25% and decreased by 30% respectively, then its perimeter becomes 540
cm. Find the original area (in cm2) of the rectangle.
Solution
Let the original length and breadth of the rectangle be 8x cm and 5x cm, respectively According to the question, 2 Γ {(1.25 Γ 8x) + (0.7 Γ 5x)} = 540 Or, 10x + 3.5x = 540 Or, x = 540/13.5 = 20 Therefore, original area of the rectangle = 8x Γ 5x = 40x2 = 16000 cm2
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