Suppose that after I wrote this problem, Richard Rusczyk thought he could be more clever than I could, so he wrote his own problem. Suppose that both of our problems are in the set of 12 problems you are currently working on. If you sat down at your computer this morning and randomly loaded 4 of the 12 problems, what is the probability that both this problem and Richard Rusczyk's problem were among the four you loaded?
I saw you posted this yesterday and got no answer....
I often get probability Q's wrong....but here is my try
12 C 4 = 495 ways to choose 4 questions
two questions in the set of 4 4 C 2 = 6 ways
So, I THINK 6 / 495 (could be wrong...and likely is)