Question:
The volume of a cube is 2744 cm2. Its surface area is
(a) 196 cm2
(b) 1176 cm2
(c) 784 cm2
(d) 588 cm2
Solution:
(b) 1176 cm2
Let the edge of the cube be a cm.
Then, volume of the cube = a3
Or,
$a^{3}=2744$
$a^{3}=\left(2^{3} \times 7^{3}\right)$
$a=2 \times 7$
$a=14 \mathrm{~cm}$
Therefore, surface area of the cube $=6 a^{2}$
$=(6 \times 14 \times 14) \mathrm{cm}^{2}$
$=1176 \mathrm{~cm}^{2}$