How many positive integers are there whose digits strictly decrease from left to right, and have at most one even digit, and the sum of the digits is 6?
How many positive integers are there whose digits strictly decrease from left to right,
and have at most one even digit, and the sum of the digits is 6?
6 0 This is legit, because zero isn't even. Somebody might argue definitions.
5 1
5 1 0
4 2 Won't work, problem says there can't be more than one even digit.
3 2 1
3 2 1 0
By the terms of the problem, I find 5 of them.
.