Sample spaces and systematic lists · Optional extension
L050 · Allow 10–15 minutes for learners ready to move on. Answers are available after an attempt.
Stretch
Two fair dice are rolled. Count the outcomes with a sum of 9 and find the probability.
Reveal a worked check after attempting
(3,6),(4,5),(5,4),(6,3): 4/36=1/9.
Deep challenge
A learner lists (1,3) and (3,1) as one outcome when two distinct dice are rolled. Explain the effect.
Reveal a worked check after attempting
The outcomes are distinct ordered pairs; merging them undercounts the total and can distort probability.