Question

you want to invite 5 of 8 friends. how many choices if: P(sum of 2 dice is odd)

Answer 1

It seems that you have mixed two questions in one and the question seems wrong or incomplete, if you wanted to ask this question, then here is the answer:

Question :- you want to invite 5 of 8 friends. How many choices if:

a) 2 of them refuse to attend together?

b) 2 of them will only attend together?

Answer:-

a) there are ⁶c₅ = 6 possible ways that 2 of them refuse to attend together  

(b) There are ⁶c₃ = 20 possible ways that 2 of them will attend together