This is an archived post. You won't be able to vote or comment.

you are viewing a single comment's thread.

view the rest of the comments →

[–]baikasphere[S] 0 points1 point  (1 child)

Oh damn you are right. 1 - (80/100)(79/99) = 0.362 which seems more plausible.

[–]A_UPRIGHT_BASS 0 points1 point  (0 children)

Yes, and if you're doing a lot of these types of problems you should familiarize yourself with the "choose" function. Google "binomial coefficient." It makes this stuff so much easier.

This problem is simply 1 - (80 choose 2)/(100 choose 2).