Jane Street interview questions

The interview was very disappointing. This was my 3rd round with the firm, the interviewer barely cared about my solutoin, was yawning, disinterested for some reason. So, yeah it was a pretty bad experience and no!! I was not doing stupid stuff in the interview it was just a bad day i believe. The question that they asked was about 10 cards on a deck and by the end they were able to make it a multiplayer game where you had to think of a winning strategy with x red and 10-x blue cards.