Direction: 125 cubes of similar size are arranged in the from of a bigger cube (5 cubes on each side, i. e., 5 x 5 x 5). From on corner of the top layer of this cube, four smaller cubes (2 x 2 x 1) are removed. From the column on the opposite side, two cubes (1 x 1 x 2) are removed, and from the third corner,three cubes (1 x 1 x 3) are removed and from the fourth column four cubes (1 x 1 x 4) are removed. All exposed faces of the block thus formed are coloured red.
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How many cubes do not have any coloured face?
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- 38
- 44
- 25
- 35
Correct Option: C
In any plane, leave 4 sides cube and select (3 x 3 x 3) inter section. But
the cubes 2 x 2 x 1 give 2 less cube because that part we are already removed.
No. of cubes = (3 x 3 x 3) - 2 = 25.
