Thread: A PROBLEM in PROBABILITY

Two deck of cards are thoroughly suffled and placed face down, side-by-side. A card from the top of each deck i turned over, then the next pair of cards is turned over, then the next, and so on until the decks are exhausted. What is the probability that on some turn over, the pair of cards match exactly????

Originally Posted by gravity2910

Two deck of cards are thoroughly suffled and placed face down, side-by-side. A card from the top of each deck i turned over, then the next pair of cards is turned over, then the next, and so on until the decks are exhausted. What is the probability that on some turn over, the pair of cards match exactly????

Hint: look up "derangments" or "hat check problem" on the web or in a textbook on combinatorics or probability.