Two fair dice are rolled. What is the probability that the sum is 7?
Answer and explanation
Correct answer: A.
- Step 1: The pairs (1,6), (2,5), (3,4), (4,3), (5,2), (6,1) sum to 7. Step 2. That is 6 favourable outcomes out of 36, so . **Answer: . Why not the others:** the sums 2 to 12 are not equally likely, and order matters when the dice are distinguished.
Practise more Algebra, Functions, Calculus and Statistics.
Free questions with an explanation for every one, and full timed Leaving Cert Ireland mock tests.