A cylindrical container of radius 6 cm and height 15 cm is filled with ice-cream. The whole icecream has to be distributed to 10 children in equal cones with hemispherical tops. If the height of the conical portion is four times the radius of its base, find the radius of the ice-cream cone. Choose the correct option.
A) 1 B) 2 C) 3 D) 4 E) 5

Rationale: volume of given ice cream = ( pie ) * 6 ² * 15 = 540 ( pie ) dividing to 10 children volume given to a child = 54 ( pie ) let r be radius and h be the height of the cone , then ( pie ) r ² h / 3 + 2 ( pie ) r ³ / 3 = 54 ( pie ) also given h = 4 r 4 r ³ / 3 + 2 r ³ / 3 = 54 2 r ³ = 54 r ³ = 27 r = 3 answer : c
Answer: C