How many five-card hands chosen from a standard deck of playing cards consist of five cards in a row (such as the nine of diamonds, the ten of clubs, jack of clubs, queen of hearts, and king of spades)? Such a hand is called a straight. What is the probability that a five-card hand is a straight? Explore whether you get the same answer by using five element sets as your model of hands or five element permutations as your model of hands.