A solid metallic sphere of radius 8cm is melted and drawn into a wire of uniform cross-section. If the length of the wire is 24m, then its radius (in mm) is ?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 ie 
(4/3) × 8³ = r² × h
(4/3) × 8³ = r² × 24
r² = (8³ × 4) / (3 × 24)
r² = (8 × 8 × 2 × 2) / (3 ×3)
r = (8 × 2)/3 = 16/3