A cube has all its faces painted with different colours. It is cut int...
(d) The number of small cubes with only one of the sides painted is 8.
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A cube has all its faces painted with different colours. It is cut int...
Solution:
Given, a cube is cut into smaller cubes of equal sizes such that the side of the small cube is one-fourth the big cube.
Let the side of the big cube be 'a'. Then, the side of the small cube is 'a/4'.
The number of small cubes in each row of the big cube is 'a/(a/4)' = 4.
Therefore, the total number of small cubes in the big cube is 4 x 4 x 4 = 64.
Now, we need to find the number of small cubes with only one of the sides painted.
There are 8 corner cubes in the big cube. Each corner cube has 3 sides painted.
There are 12 edge cubes in the big cube. Each edge cube has 2 sides painted.
There are 6 face cubes in the big cube. Each face cube has 1 side painted.
So, the total number of small cubes with only one of the sides painted is:
8 x 3 + 12 x 2 + 6 x 1 = 24 + 24 + 6 = 54
But each small cube has 6 faces. So, we need to divide the total by 6 to get the number of small cubes.
Therefore, the number of small cubes with only one of the sides painted is:
54/6 = 9
Hence, the correct option is (D) 8.
A cube has all its faces painted with different colours. It is cut int...
Yes sir answer is 24
each side is painted different color
they said that small cube side is one fourth of the big cube side
ex: if we consider four equal distances in that large cube side then the small cube side is one fourth of the big cube so that there are 16 boxes were formed in the big cube side
12 are painted with colors and four are painted with single color
like there are 6 faces in a cube. each side there are four single colored
totally 6×4 = 24
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