If the length and breadth of a rectangle are increased and decreased by 10 percent respectively, what is the percentage change in the area of the rectangle?

Explanation

Let the length of the rectangle = $x$ the width of the rectangle = $y$ $\therefore$ area of the rectangle = $xy$ According to the question 'Successively increasing the length of the rectangle by 10 percent and decreasing the width of the rectangle by 10 percent' New length of the rectangle = $x + x \times \frac{10}{100} = 1.1x$ New width of the rectangle = $y - y \times \frac{10}{100} = 0.9y$ New area = $1.1x \times 0.9y = 0.99xy$