Values of Xi include odd and even numbers,
Therefore, the sum of probabilities that the sum of values is 2 4 6 8 10 must not be 1.
When listing distribution lists, the calculation method is as follows
For example, P(ξ=2)= P 1/P2
P 1 is an even number, 2 is 5/9, and the sum of these two numbers is the probability P2 of an even number.
So the sum of probabilities in the distribution list is 1.