So here is a probability/combinations question I have stumbled across. This actually is not for homework, it is just in a textbook. Unfortunately this textbook does not give the answer for this question. I am really unsure of how you are supposed to figure this out. I imagine it has something to do with combinations or permutations, but I am completely stumped.
"A domino set has pieces that contain pairs of numbers. Each number of the pair is either 0, 1, 2, 3, 4,5, 6. In the set of pieces all pairs of numbers are present. For example: one piece has numbers (5, 6). Theorder of the numbers is not important. Pieces with a pair of numbers that are equal are also in the set.For example: one piece has numbers (3, 3). Also, each pair of numbers only appears once in the set. If I choose a piece at random from the full set of pieces and the piece I choose has two differentnumbers what is the probability that a second piece chosen at random from the remaining pieceswill have at least one number that matches either of the two numbers on the piece I chose?"