Multiple choice

If the volume of a cone is 6930 cm3 and its height is 15 cm then find the radius of the cone?

  1. 9 cm

  2. 12 cm

  3. 21 cm

  4. 18 cm

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Volume of cone = (1/3) * pi * r^2 * h. 6930 = (1/3) * (22/7) * r^2 * 15. 6930 = (22/7) * r^2 * 5. 6930 = (110/7) * r^2. r^2 = (6930 * 7) / 110 = 63 * 7 = 441. r = sqrt(441) = 21.

AI explanation

The volume of a cone formula is V equals 1 over 3 times pi times r squared times h. Substituting the given values, we write 6930 equals 1 over 3 times 22 over 7 times r squared times 15. Solving for r squared gives 441, and taking the square root results in a radius of 21 cm.

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