Correct Answer: 243 sq cm
Explanation:
Volume (new cube) = (13 + 63 + 83 ) = 729 cm3 a3 = 729 ⇒ a = ∛ 729 ∴ Surface area of the new cube = 6a2 = 6 x 92 = 486 sq cm Surface area/2 = 486/2 = 243 sq cm