Two cubes, each of volume 64 cm3, are joined end to end.

Volume of the cube = a3

Therefore,

$a^{3}=64$

$\Rightarrow a^{3}=(4)^{3}$

$\Rightarrow a=4 \mathrm{~cm}$

Each side of the cube = 4 cm

Then,

Length of the cuboid $\Rightarrow(2 \times 4) \mathrm{cm}=8 \mathrm{~cm}$

Breadth of the cuboid = 4 cm
Height of the cuboid = 4 cm

Total surface area of the cuboid $=2(l b+b h+l h)$

$=2[(8 \times 4)+(4 \times 4)+(8 \times 4)] \mathrm{cm}^{2}$

$=(2 \times 80) \mathrm{cm}^{2}$

$=160 \mathrm{~cm}^{2}$