Because the probability of winning or losing between soldiers at the same level is 50%.
The second case: Party A, Party B, ethylene propylene, ethylene propylene 2/5 * 3/5+1/4 * 2/4+(1/3 *1/2) *
So the winning probability is: 2/5 * 3/5+1/4 * 2/4+1/3 *1/3+2/5 * 3/5+1/4 * 2/4+(60.
=(6/25+ 1/8)*2+ 13/72
=0.9 1055555
Then the probability of team A winning is 0.9 1055555.