Let X be a sum of results when rolling die twice. P (X at most 5) =

Answer:The probability of sum of results when rolling dice twice giving at most 5, P (X) = 5 / 18

Step-by-step explanation:

A dice has 6 outcomes, S = [1, 2, 3, 4, 5, 6}

When two dice are rolled, the no of outcomes n (S) = 6 * 6 = 36

S = { (1, 1), (1, 2) ... (1, 6)

(2, 1) ... (2, 6)

... (6,6) }

Le X be the event that sum of two dice when rolled is at most 5

At most refers to lesser than or equal to,

Therefore the outcomes for event X = { (1, 1), (1, 2), (1, 3), (1, 4), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (4, 1) }

n (X) = 10

P (X) = n (X) / n (S)

= 10 / 36 = 5 / 18