Question 742300
There are 8 C 4 = 70 ways to choose a group with all women.


Note: I'm using the formula shown <a href="http://en.wikipedia.org/wiki/Combination">here</a>


There are 13 C 4 = 715 ways to choose a group of men and women.


So there are 715 - 70  = 645 ways to choose a group with at least one man.


This means the probability is 645/715 = 129/143 = 0.9020979 (so roughly a 90.20979% chance)