GMAT Problem Solving (PS) | Re: What is the % change in the area of a rectangle when its len

What is the % change in the area of a rectangle when its length increases by 10% and its width decreases by 10%?
A. 0%
B. 20% increase
C. 20% decrease
D. 1% decrease
E. Insufficient data

Let Length be = 2
Let width be = 1
Area of rectangle = Length x width = 2 x 1 = 2
Length increases by 10% = 110% of 2 =\(\frac{110}{100}\) x 2 = 2.2
Width decreases by 10% = 90% of 1 =\(\frac{90}{100}\) x 1 = 0.9
New area of rectangle = 2.2 x 0.9 = 1.98

Change in Area = 2 - 1.98 = 0.02

Percentage Change = Change in Area / Initial
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