- 1 and 11 - 2 and 12 - 3 and 13 - 4 and 14 - 5 and 15
Each outcome technically has two ways of occurring, but since we're taking two marbles at a time, that would be the same as saying, for instance, that drawing 1 and 11 is the same as drawing 11 and 1. We only count such an event once.