Official ExplanationIn this question you are asked to compare the area of rectangle A and the area of rectangle B. Since the information given relates the dimensions of both rectangle A and rectangle B to the corresponding dimensions of rectangle C, you can try to use the relationships to make the desired comparison.
If ℓ represents the length of rectangle C and w represents its width, then the length and width of rectangles A and B can be translated into algebraic expressions as follows.
- The length of rectangle A is 10 percent greater than the length of rectangle C, or 1.1ℓ.
- The width of rectangle A is 10 percent less than the width of rectangle C, or 0.9w.
- The length of rectangle B is 20 percent greater than the length of rectangle C, or 1.2ℓ.
- The width of rectangle B is 20 percent less than the width of rectangle C, or 0.8w.
In terms of ℓ and w, the area of rectangle A is (1.1ℓ)(0.9w), or 0.99ℓw.
In terms of ℓ and w, the area of rectangle B is (1.2ℓ)(0.8w), or 0.96ℓw.
Since 0.99ℓw is greater than 0.96ℓw, Quantity A is greater than Quantity B, and the correct answer is Choice A.