Given that,
Volume of cubes = 64 cm3
(Edge) 3 = 64
Edge = 4 cm
If cubes are joined end to end, the dimensions of the resulting cuboid will be 4 cm, 4 cm, 8 cm.
Therefore , The surface area of cubiod = 2(lb+bh+hl)
=2(4 x 4+ 4 x 8+ 4 x 8)
=2(16+32+32)
=2 x 80=160 cm2