The problem
You roll two fair dice. What is the probability the total is 11? Give a fraction.
Answer
P = 1/18
Worked solution
- There are 6 × 6 = 36 equally likely outcomes.
- Pairs that make 11: (5,6) (6,5) = 2 ways.
- P = 2/36 = 1/18
How members answered
- 29tried
- 48%first try
- 16solved
Common mistakes
- There are 11 possible totals, but they aren’t equally likely: 7 can happen 6 ways, 2 only 1 way. Count outcomes out of 36. (1 person)
Top wrong answers: 7 (2), 11 (2).