Three cubes of equal volume are joined end to end. Find the surface area of the resulting cuboid if the diagonal of the cube is $6\sqrt{3}$cm.

504 cm²

We know that,

Diagonal of cube = \(\sqrt {3}\) × Side of cube

= 6\(\sqrt {3}\) = side \(\sqrt {3}\)

Side = 6

So, length of cuboid = 3 × 6 = 18 

Breadth = 6

Height= 6

The surface area of the cuboid = 2(lb + bh + lh)

= 2(108 + 36 + 108) = 2 × 252 cm² = 504 cm²