Multiple choice

The width of a square increases by $30\%$. By what percent does its area increase?

  1. $30\%$
  2. $69\%$
  3. $90\%$
  4. $105\%$
  5. $900\%$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Area = s^2. New side = 1.3s. New area = (1.3s)^2 = 1.69s^2. Increase = 1.69 - 1 = 0.69 or 69%.

AI explanation

Let the original side of the square be 10, making the initial area 100. A 30% increase in the side length makes the new side 13, which gives a new area of 169. The increase in area is 69. The percentage increase is (69 / 100) times 100, which is 69%.

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