Multiple choice

Find the volume of the frustum cone whose base and top radius is 4 mm and 2 mm respectively. The height of the cone is 27 mm. (Use $\pi$ = 3.14).

  1. 781.28 mm$^3$
  2. 791.28 mm$^3$
  3. 761.28 mm$^3$
  4. 711.28 mm$^3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Volume of frustum = (1/3) * pi * h * (R^2 + r^2 + R*r). V = (1/3) * 3.14 * 27 * (4^2 + 2^2 + 4*2) = 3.14 * 9 * (16 + 4 + 8) = 3.14 * 9 * 28 = 791.28.

AI explanation

Apply the frustum of a cone volume formula V = (1/3) pi h (R squared + Rr + r squared) using R = 4 mm, r = 2 mm, h = 27 mm, and pi = 3.14. Calculate the bracket sum as 4 squared + 4 times 2 + 2 squared, which equals 28. The volume is (1/3) times 3.14 times 27 times 28, giving 791.28 cubic mm.

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