If the length of a rectangular plot is increased by 25%, by what percentage should the width be adjusted to maintain the same area?

Explanation

Assume the original length is x and width is y, so the area is xy. After increasing the length by 25%, the new length becomes (5x/4). To keep the area constant, new width w must satisfy (5x/4) * w = xy, which gives w = (4y/5). This means the width is reduced by (y - 4y/5) = y/5, which is a 20% decrease.