Theory question 105
ProbabilityTwo fair dice are tossed together once. (a) Draw the sample space for the possible outcomes. (b) Find the probability of getting a total: (i) of 7 or 8; (ii) less than 4.
Show the model answer
Model answer
(a) A 6 × 6 table of pairs (1,1) to (6,6), or of totals 2 to 12: 36 equally likely outcomes.
(b)(i) Total 7: 6 outcomes; total 8: 5 outcomes. P = 11/36.
(ii) Total less than 4 (2 or 3): (1,1), (1,2), (2,1) = 3 outcomes. P = 3/36 = 1/12.
Explanation
Count outcomes from the sample space and divide by 36.