Question

Three metal cubes of 6 cm, 8 cm and 10 cm are melted and recast into a big cube. 3Find its total surface area.

Answer 1

Let the length of each edge of the new cube be a cm. Then

a

3

=(6

3

+8

3

+10

3

)cm

3

⇒a

3

=1728⇒a=12

Volume of the new cube =a

3

=1728cm

3

Surface Area of the new cube =6a

2

=6×12

2

cm

2

=864cm

2

Diagonal of the new cube =

3

a=12

3

cm