Question

how many 5cm cubes can be cut from a cube whose edge is 20cm

Answer 1

No. of 5cm cubes that can be cut =
volume of 20cm cube /volume of 5cm cube
= 20^3/5^3
= 20×20×20/5×5×5
=4×4×4
= 64


Therefore 64 cubes can be cut off

Answer 2

The number of small cubes that can be obtained from the large cube is 64.

Given,

The edge length of the large cube = 20 cm

The edge length of the small cube = 5 cm

To Find,

Number of small cubes that can be obtained from the large cube

Solution,

We know that in this case, the volume will remain constant.

Thus we can say that -

The volume of the Large cube = Total volume of all small cubes

Let the number of small cubes obtained = n

The volume of a cube is given as

Volume = (Edge length)³

The volume of the Large cube = Total volume of all small cubes

(20)³ = n*(5)³

20 x 20 x 20 = n x 5 x 5 x 5

n = $\frac{8000}{125}$

n = 64

Hence, 64 cubes can be obtained.

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