Parikshit makes a cuboid of plasticine of sides 5 cm, 2 cm, 5 cm. How many such cuboids will he need to form a cube?

As per the question,

There are ome cuboids of size 5 x 2 x 5

Now,

When these cuboids are arranged to form a cube, the side of this cube so formed is going to be a common multiple of the sides (i.e., 5, 2, and 5) of the cuboid.

So,

LCM of 5, 2, and 5 = 10

Let us try to make a cube of 10 cm side

For this arrangement, we have to put:

2 cuboids along with its length,

5 along with its width

And,

2 along with its height

Total cuboids required according to this arrangement = 2 x 5 x 2

= 20

With the help of 20 cuboids of such measures, a cube is formed as follows: