Since the pips on each end of the domino tiles must match, the answer, then, is computed by determining the likelihood of two tiles having a matching pip divided by the total number of possibilities. The likelihood of two dominoes having matching pips is C(7, 2) or 147. Their are 378 possible combinations of 2 dominoes from the 28 domino set, C(28, 2). The odds are then 147/378 or 7/18.
