Question 266109
It may be easier to understand the solution, by setting up a table as follows:
levels . 0 face paint//1 face paint//2 face paint//3 face paint//4 face paint//5 face paint//6 face paint//ttl
1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. . . . . . . . . . . . . . . . .5
2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 . . . . . . . . . . 4. . . . . . . . . . . . . . . . . . 1. . . . . . . . . . . . . . . . 25
3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 . . . . . . . . . 8. . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . .61
4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 . . . . . . . . . 12 . . . . . . . . . . . . . . . . . 1. . . . . . . . . . . . . . . .113

notice that we have a patterns here:
2 faces = 4*(level - 1)^2
3 faces = 4*(level - 1)
5 faces = 1
The number of total cubes is
(level)*(level + 1)*(2*level + 1)
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If we go to 10 stories, then we get
2 faces = 4*9^2 = 4 * 81 = 324
3 faces = 4*9 = 36
5 faces = 1 = 5
added, we get 365 total faces painted
there are a total of 338,350 cubes
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