Question

If each edge of a cube is made four times the original length, how many times will its total surface area increase?

• A. 4
• B. 16
• C. 2
• D. 8

Answer 1

The correct option is B 16

Let the edge of a cube be $l$.
The total surface area (A) of the cube = $6l^2$
When edge of cube is increased to four times, then the total surface area (A') of the cube $=6(4l{)}^2$
$=6\times 16l^2$
$=16\times 6l^2$
$=16\times A$
Hence, the new total surface area will increase by 16 times the original total surface area.