If the length of a square is increased by 20% while its width is decreased by 20% to form a rectangle, what is the ratio of the area of the rectangle to the area of the square?
Worked solution (try it first)
Take the square's side as 1.
The rectangle is 1.2 by 0.8, so its area is 1.2×0.8=0.96.
The square's area is 1, so the ratio is 0.96:1=96:100, which simplifies to 24:25, option D.