The $2018$ Champions League quarterfinal draw will take place on Friday, March $16^{th}, 2018$ and I wanted to know what is the likelihood that Barcelona will get paired up with Real Madrid? There are $8$ teams left in the pool so a total of $4$ draws will be made.
I think that the number of ways to pairing Barcelona v Real Madrid is $^8C_2$ but I am stuck on how many possible draws there are. Isn't it $\dfrac{^8C_2}{\text{total # of draws}}$?
If someone can walk me through the solution to this problem that would greatly be appreciated. Probability has always given me trouble...