A player draws the cards from the a 52-card deck one by one, without putting them back in the deck.
Every time before drawing a card he guesses the suit of the card he will draw.
He decides to always guess the suit that occurs most frequently in the remaining deck (if there are several such suits, he chooses any one of them).

Prove that he will guess the right suit at least 13 times.

(In reply to Analysis (spoiler) by puzzlesrfun)

Your solution seems to be assuming binomial trials which requires the trials to be independent.  The trials are NOT independent because each guess is made using the information from the previous draws. 

Posted by Jer on 2015-07-29 19:01:37