When two dice are rolled, the probability that the sum of points on them is even or less than 5 points is
- $\dfrac{7}{9}$
- $\dfrac{5}{9}$
- $\dfrac{4}{9}$
- $\dfrac{3}{9}$
Total outcomes for two dice = 36. Even sums: (1,1), (1,3), (1,5), (2,2), (2,4), (2,6), (3,1), (3,3), (3,5), (4,2), (4,4), (4,6), (5,1), (5,3), (5,5), (6,2), (6,4), (6,6) = 18 outcomes. Sums less than 5: (1,1), (1,2), (1,3), (2,1), (2,2), (3,1) = 6 outcomes. The union includes (1,1), (1,3), (2,2), (3,1) which are in both sets. Total unique outcomes = 18 + 6 - 4 = 20. Probability = 20/36 = 5/9.
When two dice are rolled, there are 36 total possible outcomes, and 18 of these result in an even sum. The sums that are strictly less than 5 are 2, 3, and 4, which account for 6 outcomes, and these are all either even or odd. Because all strictly less than 5 outcomes that are not already counted in the even sums are the odd sums of 3, we apply the addition rule: 18/36 plus 2/36 equals 20/36, which simplifies to 5/9.