An order was placed for the supply of a carper whose length and breadth were in the ratio of 3 : 2. Subsequently, the dimensions of the carpet were altered such that its length and breadth were in the ratio 7 : 3 but were was no change in its parameter. Find the ratio of the areas of the carpets in both the cases.
Correct answer: B. 8 : 7
- A. 4 : 3
- B. 8 : 7
- C. 4 : 1
- D. 6 : 5
Explanation
Let the original dimensions be 3k and 2k, so the perimeter is 10k. If the new dimensions are 7m and 3m, their perimeter is 20m, giving m = k/2. The areas are 6k^2 and 21k^2/4, so their ratio is 6 : 21/4 = 8 : 7. Option a is the common error from comparing the dimension ratios instead of calculating areas.
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