+64 How many integers can be formed by using the digits 1, 2, and 3 each at most once?
+118653 Well, guest has neamed all the 3 digit ones but it says 'at most' so I am going to interpret this question to mean that no other digits can be used but these three do not all need ot be used either.
So I will take the 6 already named and add
1,2,3,12,13,21,23,31,32 that is 9 more - so I will say 9+6=15
