Reasoning Class 7 Cubes and Dice

Asked by RAJANYA MONDAL · The Level field School

A cube is divided into n^3 smaller cubes. The formula to find the number of smaller cubes with no painted face is:

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Answer: A. (n-2)^3

Cubes with no painted face lie fully inside, away from all six outer faces. Removing one layer from each side leaves an inner block of (n - 2) x (n - 2) x (n - 2) = (n - 2)^3 cubes. 6(n - 2)^2 counts cubes with one face painted.

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