Question

Parikshit makes a cuboid of plastic of side $5$ cm, $2$ cm, $5$ cm. How many such cuboids will be need to form a cube?

Answer 1

Let us calculate the LCM of $5$ and $2$. The cube with each sides measuring equal to the LCM will give the dimensions of required cube.

LCM of $5$ and $2=10$

Volume of cuboid $=5\times 5\times 2$ cubic cms

Volume of bigger cube $=103=1000$ cubic cms

Number of cuboids required to make the bigger cube can be found as volume of bigger cube divided by volume of cuboid that is:

$\frac{1000}{50}=20$

Hence, $20$ cuboids will be needed to form a cube.