basic_probability.md

Link to task: Basic Probability

Task:

In a single toss of 2 fair (evenly-weighted) six-sided dice, find the probability that their sum will be at most 9.

Solution:

• Sample space (Ω): {1, 2, 3, 4, 5, 6} * {1, 2, 3, 4, 5, 6}
• Event A := "Sum of both dice is greater than 9" = {(6, 4), (6, 5), (6, 6), (5, 5), (5, 6), (4, 6)}
• Event B := "Sum of both dice is at most than 9", therfore |B| = |Ω| - |A| = 36 - 6 = 30
• P(B) = |B| / |Ω| = 30 / 36 = 5 / 6

Probabilty that the sum of both dice will be at most 9 is 5/6.