Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: 2005 · Marks: · Difficulty:
If the total length of diagonals of a cube is 12 cm, then what is the total length of the edges of the cube?
(a)$6 \sqrt{3} \mathrm{cm}$
(b)12 cm
(c)15 cm
(d)$12 \sqrt{3} \mathrm{cm}$
Answer
Answer (as printed): C
Explanation
Since a cube has 4 diagonals, we have: Length of a diagonal $=\left(\frac{12}{4}\right) \mathrm{cm}=3 \mathrm{cm}$. Let the length of each edge of the cube be $a \mathrm{cm}$. Then, $\sqrt{3} a=3$ or $a=\sqrt{3}$. ∴ Total length of the edges of the cube $=12 \sqrt{3} \mathrm{cm}$.