Question

Two identical cubes each of total surface area of $6c{m}^2$ are joined end to end. Which of the following is the total surface area of the cuboid so formed?

• A. $8c{m}^2$
• B. $18c{m}^2$
• C. $12c{m}^2$
• D. $10c{m}^2$

Answer 1

The correct option is D $10c{m}^2$

The total surface area of two cubes $=2\times 6c{m}^2=12c{m}^2$
Area of one face of the cube $=1c{m}^2$
Now, if the two cubes are clubbed together, they are we have to subtract two surface which gets hidden.

So, total surface area of the new cuboid $=12c{m}^2-2c{m}^2=10c{m}^2$