For each password character, there are 26+26+10=62 possibilities. That brings the total number of possible passwords to 62⁶ if we wouldn't consider the additional constraints.
- No passwords without numbers allowed, so we subtract 52⁶ - No passwords without uppercase allowed, so we subtract 36⁶ - No passwords without lowercase allowed, so we subtract 36⁶
Now we have subtracted the passwords of all capitals twice, so we have to add those back in: add 26⁶ Same for all lowercase and all numbers: add 26⁶ and 10⁶
end result: 62⁶ -52⁶-36⁶-36⁶ + 26⁶+26⁶+10⁶ = 33294892800
It is ten units, as the two sides are of 6 and 8 so you must square them both, add them together (which gives you 100) and then square root that, which gives you 10
