Let the length of side of a cube = a cm
Given, volume of the cube ,`a^(3) = 64 cm^(3) rArr a = 4 cm`
On joining two cubes, we get a cuboid whose
Length ,l = 2a cm
breadth, b= a cm
and " " height , h = a cm
Now, surface area of the resulting cuboid cuboid = 2 (lb + bh + hl)
`" "=2 (2a. a+ a.a+a.2a)`
`" "= (2 (2a^(2) + a^(2) + 2a^(2)) = 2 (5a^(2))`
`" " = 10a^(2) = 10(4)^(2) = 160 cm^(2)`
