Multiple choice

A rectangular piece of metal with sides $24\ cm$ and $18\ cm$ costs Rs. $1080$. How much will a square piece of the same metal of side $16\ cm$ cost if the cost of metal is proportional to its area.

  1. Rs. $840$
  2. Rs. $640$
  3. Rs. $720$
  4. Rs. $900$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Area of rectangle = 24 * 18 = 432 cm^2. Cost per unit area = 1080 / 432 = 2.5 Rs/cm^2. Area of square = 16 * 16 = 256 cm^2. Cost = 256 * 2.5 = 640.

AI explanation

Using the area of a rectangle formula, the initial area is 24 cm multiplied by 18 cm, which equals 432 sq cm, yielding a rate of 1080 divided by 432, or Rs. 2.5 per sq cm. The area of the square is 16 squared, which is 256 sq cm. Multiplying this area by the rate gives a total cost of 256 multiplied by 2.5, resulting in Rs. 640.

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