Question

The length of a rectangle is increased by 20%. The width of same rectangle is decreased by 20%.

By what percentage is the area changed?

Answer 1

4%

Explanation:

Let the original length be l, the original length be w. The area is lw.

After the change, the length is 1.2l and the width is 0.8w. So, the area is 0.96lw.

This means the area has changed by 4%.