504 cones, each of diameter 3.5 cm and height 3 cm, are melted and recast into a metallic sphere. Find the diameter of the sphere. Use π=22/7

Given r=3.5/2 cm and h=3 cm
Volume of cone = (1/3)πr²h
Volume of cone = (1/3)π(3.5/2)²×3 = (1/3)×(22/7)×(3.5/2)×(3.5/2)×3 = 19.25 cm³
Volume of 504 cones = 504 × 19.25 = 9676.5 cm³
Volume of sphere = (4/3)πr³
Cones are melted and recast in sphere
∴ (4/3)×(22/7)r³ = 9702
→ r³ = 9702 × (3/4) × (7/22) = 2205
→ r = ∛2205 = 13.02 cm (approx)
Diameter of sphere = 2 × 13.02 = 26.04 cm (approx)