The volume of a cone is 73920 cm3. If the height of the cone is 160cm, then find the diameter of its base.
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Correct answer: D
Explanation
The correct answer is option 4 i.e. 42cm.
The volume of a cone is 73920 cm3.
If the height (h) of the cone is 160 cm,
The volume of a cone V = 1/3hπr²
⇒ V = (1/3)πr2h
⇒ 73920 = (1/3) × (22/7) × r2 × 160
⇒ r2 = 441
⇒ r = 21 cm
Hence, the diameter of the base of the cone = 2 r = 2 × 21 = 42 cm