A solid metallic cone is melted and recast into a solid cylinder of same base as that of cone. If the height of the cylinder was 7 cm, the height of the cone is:
Answer & explanation
Correct answer: option 2
Vol of cone = vol of cylinder
⇒ \(\frac{1}{3}\)\(\pi \) r2h = \(\pi \) r2H
⇒ \(\frac{1}{3}\)\(\pi \) r2h = \(\pi \) r2× 7
⇒ h = 21 cm.