Volume of each cube =64cm3=lenght3
Then, length= 3√64=4cm
Then when the two cubes are merged, the length increases whereas the base and height remains intact. Hence the dimension becomes : 8×4×4
So the Lateral Surface area of the cuboid =2h(l+b)=2×4(12)=96cm2
Total surface area of the cuboid =2(lb+bh+lh)=2(32+16+32)=160cm2