If a right circular solid cylinder of base radius 7 cm and height 28 cm is melted to form a cuboid such that the ratio of its side is 2 : 3 : 6. Then find the total surface area (in sq. cm) of cuboid?

Cylinder volume = πr²h = π × 7² × 28 = 4312π/3 cm³ (using π = 22/7). This becomes cuboid volume. If sides are in ratio 2:3:6, let sides be 2k, 3k, 6k. Volume = 36k³ = 4312π/3, so k³ = 1078π/9 and k = (1078π/9)^(1/3). Surface area = 2(2k×3k + 2k×6k + 3k×6k) = 2(6k² + 12k² + 18k²) = 72k² = 72 × (1078π/9)^(2/3). This matches option A. The other options have incorrect coefficients or fractional powers.