Question

Rahul makes a cuboid of plasticine of sides 3cm*3 cm*5 cm. How many such cuboids will he need to form a cube .

Answer 1

Prime factorisation
(So that we can find the number to multiply to get perfect cube)

so the prime factors are 3 , 3 and 5
We must have triplets in the factors.If triplets are not there we should multiply the numbers such as there is a pair of 3 and single 5 so one 3 is less from its triplet and pair of 5 is less from its triplet.

So multiply these numbers 3*5*5=75

Therefore 75 number of cuboids are necessary to form a cube.

Answer 2

Answer:

He requires 75 such cuboids to form a cube.

Step-by-step explanation:

Vol. of cuboid = ( 3×3×5 ) cm^3

= 45 cm^3

Each side of a cube will be = ( LCM of 3, 3 & 5. ) cm

= 15 cm

Therefore, Vol. of cube = 3375 cm^3

Therefore, No. of cuboids required = vol. of cube / vol. of cuboid

= 3375 / 45

= 75 (ans.)