Question

A solid cube of 12cm has been painted green

Answer 1

Answer:

Ans is 72

Step-by-step explanation:

Because cube have 6 sides =12×6=72

You can do calculator also

Answer 2

Given:

The edge length of the cube (L)= 12cm

Green and yellow are painted on adjacent sides

Blue is painted on the opposite side

The edge length of smaller cubes (l)= 4cm

To find:

Number of smaller cubes with no face painted

Solution:

Let the number of smaller cubes obtained by cutting the larger cube be n.

Using volume conservation,

L³ = n X l³

or n = 12³ / 4³

= 27

So the larger cube is cut into 3 X 3 rows and columns with one cube at the center and the remaining 26 cubes on faces. (Like in a Rubix cube)

So, the center cube is the only cube having 0 painted faces.

Hence, the number of smaller cubes with no face painted is one.

(The complete ques is: A solid cube of 12 cm has been painted green on two adjacent sides, yellow on the other two adjacent sides, and blue on two opposite sides. It is then cut into cubical blocks of side 4 cm each.  How many cubes have no face painted?)