Question:

The volume of a cube is 343 cm3. Its total surface area is

(a) 196 cm2

(b) 49 cm2

(c) 294 cm2

(d) 147 cm2

Solution:

(c) $294 \mathrm{~cm}^{2}$

Volume $=a^{3}=343 \mathrm{~cm}^{3}$

$\Rightarrow a=\sqrt[3]{343}=7 \mathrm{~cm}$

$\therefore$ Total surface area $=6 a^{2}=6 \times 7 \times 7=294 \mathrm{~cm}^{2}$