Madhya Pradesh Police Exam Model Paper 7

Given:
The surface area of a large cube is $2646\mathit{c}{\mathit{m}}^2$ and the smaller cube is $294\mathit{c}{\mathit{m}}^2$
Concept:
Side of cube = $\sqrt{\mathrm{Surface}\mathrm{area}/6}$
Number of cube = Volume of the larger cube/Volume of the smaller cube
Calculation:
In a larger cube, the side is
$\Rightarrow \sqrt{2646/6}$
$\Rightarrow \sqrt{441}$
$\Rightarrow 21\mathit{c}\mathit{m}$
In a smaller cube, the side is
$\Rightarrow \sqrt{294/6}$
$\Rightarrow \sqrt{49}$
$\Rightarrow 7\mathit{c}\mathit{m}$
Now, The number of the smaller cube is formed from the larger cube is
$\Rightarrow 21\times 21\times 21/\left(7\times 7\times 7\right)$
$\Rightarrow 3\times 3\times 3$
$\Rightarrow 27$
∴ 27