>>11023078Cheese OP come up with a harder one next time, did it in my head. The answer is 243.
3choose1 ways to pick which of the three numbers 000-999 is the 5
the remaining 2 numbers can be any of 1-9 digits (can't be 5)
so it's 3*9*9
This is like elementary school combinatorics, in Canada we take this after calculus in kindergarten.
