The height of a cone is 30 cm. It is cut by a plane at height 10 cm from the base. What percent of the cone’s volume lies above the cut?
Show answer & explanation
Correct answer: B
Explanation
Total height of the cone = 30 cm, Height of the cut section = 10 cm
According to the formula:
Ratio of the volumes of similar cones = (Ratio of heights)³
Height of the upper smaller cone = 30 − 10 = 20 cm
Ratio = (20/30)³ = (2/3)³ = 8/27
Percentage = (8/27) × 100 = 29.60%