Felix, Gene and Hank play a challenge tennis tournament where two of them play a set, then the winner stays in the court to play the one who sat out.

During the tournament, Felix played 15 sets, Gene played 14 and Hank played 9.

Who played in set 13?

They played a total of (15 + 14 + 9)/2 = 19 sets between them.

At worst, even if a person loses every game they play, they'll play every other set.  The minimum number of sets a person can play in is 9, which occurs if they play in (and lose) every even-numbered set.  Since Hank played only 9 sets, this is what he did, and thus Felix and Gene played each other in set 13. 

Posted by tomarken on 2014-04-01 11:12:08