If the length of a square is increased by 20% while 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?

  • A 6 : 5
  • B 25 : 24
  • C 5 : 6
  • D 24 : 25
jamb 1987mathematics

The correct answer is D. 24 : 25

Length and width of a square is 100%

Length increased by 20% and

Width decreased by 20% to form a rectangle

Length of rectangle = 120% to form a rectangle

Length of rectangle = 120% and

Width of rectangle = 80%

Area of rectangle = L x W

Area of square = W

Ratio of the area of the rectangle to the area of the square

A = \(\frac{\text{Area of rectangle}}{\text{Area of square}}\)

\(\frac{120 \times 30}{100 \times 100}\) = \(\frac{96}{100}\)

= 24 : 25

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