A piece of cloth costs 10,000. If a 2 m longer piece of the same cloth is purchased for the same amount, it would cost 250 less per metre. What is the original length of the piece of cloth?
- A. 8 m ✓
- B. 10 m
- C. 12 m
- D. 16 m
Correct Answer: A. 8 m
Explanation
Let original length be x. \frac{10000}{x} - \frac{10000}{x+2} = 250. Dividing by 250 yields \frac{40}{x} - \frac{40}{x+2} = 1 \implies 40(x+2) - 40x = x(x+2) \implies x^2 + 2x - 80 = 0. Solving gives x=8.
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