## anonymous one year ago You have 6 friends who want to go to a concert with you, but you only have room in your car for 2 of them. To avoid accusations of favoritism, you have your friends draw straws: There are 4 long and 2 short straws. How many possible pairs of friends can be chosen this way?

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1. anonymous

Of the 6 friends, call them $$a,b,c,d,e,f$$, you are selecting 2. It doesn't matter what the order is. What this means is that picking $$a$$ then $$b$$ is the same as picking $$b$$ then $$a$$. This means you're counting the number of combinations. $\binom62={}_6C_2=\frac{6!}{2!(6-2)!}$