Question

Answer the question no. 8

Answer 1

By L.C.M method
15,30,15's  lcm is 30 
So multiply to get 30,
15*2=30
30*1=30
15*2=30
So the cuboids needed are 2*2*1=4
HOPE THIS HELPS 
PLS MARK AS BRAINLIEST

Answer 2

Method - 1:

Given sides of a cuboid are 15cm, 30cm and 15cm.

LCM of 15,30,15 = 30.

Volume of such a cube = s^3

                                        = 30 * 30 * 30

                                        = 27000.


Volume of original cuboid = 15 * 30 * 15

                                            = 6750.



Number of cuboids required = 27000/6750

                                                = 4.



Therefore, 4 cuboids are required to form a cube.




Method - 2:

Given volume of a cube of sides 15cm, 30 and 15cm.

= > 15 * 30 * 15

= > 3 * 5 * 2 * 3 * 5 * 3 * 5

Here, two 2's are left which does not form a triplet.

In order to make it a perfect cube, multiply this expression by 2 * 2 = 4, then it will become a perfect cube.

= > 3 * 3 * 3 * 5 * 5 * 5 * 2 * 2 * 2

= > 27000 is a perfect cube.



Therefore 4 cuboids are required to form a cube.



Hope this helps!