SAT试题类型 Mathematics > Standard Multiple Choice Read the following SAT test question and then click on a button to select your answer. The length of a rectangle is increased by 20%, and the width of the rectangle is increased by 30%. By what percentage will the area of the rectangle be increased? (A) 25% (B) 36% (C) 50% (D) 56% (E) 60% 答案：D 解析：

Let and be the original length and width of the rectangle, respectively. If we denote by and the new length and width of the rectangle, respectively, then we have:

and

So, the new area will be:

where () is the original area of the rectangle. So the area is increased by .

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