Answer to Question #259734 in Discrete Mathematics for rtf

Question

Two dice are rolled. How many outcomes give the sum of 7 or the sum of 11?

Answer 1

The following outcomes give the sum of 7: (1,6); (6,1); (5,2); (2,5); (3,4) and (4,3). It follows that there are 6 such outcomes.

The following outcomes give the sum of 11: (5,6); (6,5). It follows that there are 2 such outcomes.

By Combinatorial Sum Principle, the sum of 7 or the sum of 11 give 6+2=8 outcomes.