Question 1122845
<br>
Each senator can vote either of 2 ways.<br>
The number of different ways the 100 senators can vote is 2^100.<br>
That total number of ways, 2^100, is equal to<br>
100C0 + 100C1 + 100C2 + ... + 100C99 + 100C100<br>
The only way not to get a majority (one way or the other) is if the vote is 50-50.  The number of ways that can happen is 100C50.<br>
So the number of ways to get a majority (one way or the other) is then<br>
2^100 - 100C50<br>
If you mean the number of ways of getting a majority "yes" votes, it is<br>
(2^100 - 100C50)/2