Question

The edge of a cube is $20cm$. How many small cubes of $5cm$ edge can be formed from this cube?

• A. $4$
• B. $32$
• C. $64$
• D. $100$

Answer 1

The correct option is C $64$

Volume of a cube $=(side{)}^3$.

Given, side $=20cm$.

Then, Volume $=20\times 20\times 20=8000c{m}^3$.

Also, Side of smaller cube=$5cm$.

Then, Volume $=5\times 5\times 5=125c{m}^3$.

Let the number of smaller cubes be $x$.

Then, $x\times 125=8000$.

Therefore, Number of small cubes formed $=\frac{8000}{125}=64$.

Hence, option $C$ is correct.