A frustum of a right circular cone, whose height is 18 cm, large base radius is 25 cm, and small base radius is 20 cm, is melted to form a small sphere of diameter 2 cm. How many spheres will be formed?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 6862.
Volume of right circular cone = πh/3 × (R2 + Rr + r2)
⇒ 18π/3 × (252 + 25 × 20 + 202)
⇒ π × 6 × (625 + 500 + 400) = 9150π cm3
Volume of Sphere = 4/3πr3
⇒ 4/3 × π × 13 = 4/3 × π
The number of spheres will be formed
n × 4/3 × π = 9150π
⇒ n = 6862.5
Therefore, the number of spheres that can be formed is 6862.