A hollow sphere of external and internal diameters of 10 cm and 6 cm respectively, is melted and made into another solid in the shape of a right circular cone of base diameter 10 cm. Find the height of the cone.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 15.68 cm.
Given that
External and internal diameters of the hollow sphere = 10 and 6 cm respectively
Hence, external and internal radius = 5 and 3 cm respectively
Radius and height of cone = 5 cm and h respectively
According to the question
The volume of the hollow sphere = volume of the cone
Volume of hollow sphere = π(R3 - r3)
Volume of cone = πr2h
Hence, π(53 - 33) = π(5)2h
Solving for h we get
h = 15.68 cm
Hence, the height of the cone is 15.68 cm.