Question

The cost of painting a cube is ₹$2/c{m}^2$. How much does it cost if a cube of side 3 cm is painted on all its sides?

• A. ₹128
• B. ₹54
• C. ₹108
• D. ₹64

Answer 1

The correct option is C ₹108

We know, the total surface area of a cube is given by $6a^2$, where a is the side of the cube.
Therefore, total surface area of the given cube = $6\times 3^2$ = $54c{m}^2$
Given, the cost of painting is $₹2/c{m}^2$.
Hence, the cost of painting the cube
$=2\times 54=₹108$