I'm trying to find the number of 4-digits even numbers, such that no digit repeats.
This is simple, and the solution is 2296, as is explained in How many $4$ digit even numbers have all $4$ digits distinct?
I've tried solving it with complementary sets: "The number of 4-digits even numbers" minus "The number of 4-digits even numbers such that all the digits are the same"
However with the second approach I get 4996. What am I missing? can I find the solution using complementary sets?