Three equal cubes

Given,

Let length of an edge of three equal cubes = a

Total surface area of 3 cubes = 3× 6a² = 18a²

(While putting these cubes in a row adjacently, a cuboid is formed)

∴ length of cuboid = 3a

Breadth of cuboid = a

Height of cuboid = a

So,

total surface area of cuboid = 2(3a²+a²+3a²) = 14 a²

Hence,