Multiple choice

Find the surface area of a frustum of cone, whose larger and smaller radius is 10 and 2 mm. The slant height of the cone is 15 mm.

  1. 274$\pi$ mm$^2$
  2. 264$\pi$ mm$^2$
  3. 284$\pi$ mm$^2$
  4. 254$\pi$ mm$^2$
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C Correct answer
AI explanation

The total surface area of a frustum is pi multiplied by the sum of the radii and the slant height, plus pi multiplied by the square of the smaller radius, plus pi multiplied by the square of the larger radius. Substituting the given values gives pi multiplied by 12 multiplied by 15, plus pi multiplied by 2 squared, plus pi multiplied by 10 squared. This simplifies to 180 times pi plus 4 times pi plus 100 times pi. The total surface area is 284 times pi square millimeters.

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