A rectangular floor's length exceeds its breadth by 200%. Painting it at Rs. 3 per sq m costs Rs. 324. What is the floor's length?
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Answer: C. 18 m
Explanation
Total floor area is calculated by dividing the total painting cost of three hundred twenty four by the rate of three. The length exceeds the breadth by two hundred percent, making the length equal to three times the breadth. Multiplying length by breadth gives three times the square of breadth, which equals one hundred eight, resulting in a length of eighteen. Percentage increases exceeding one hundred percent mean the new value is multiple times the original base. Rectangular area is the product of its length and breadth dimensions expressed in square units. Cost calculations link total expenses directly to surface area and unit pricing rates.
Option A overestimates the length based on an incorrect area calculation. Option B results from a minor error in solving the quadratic area equation for breadth. Option D suggests a length dimension that does not satisfy the total area and cost constraints.
- Subject
- Mathematics
- Category
- Mathematics
- Topic
- —
- Difficulty
- medium
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