If two dice are rolled once and one die rolled a second time if the first two rolls have same number, what is the probability that the two or three rolls will sum to over 15?
1 Answer
Oct 28, 2015
probability
Explanation:
If the first two rolls have the same value there are only 2 possibilities for which the sum of the 3 rolls exceeds 15.
#{: (color(black)("roll 1"),color(black)("roll 2"),color(black)("roll 3")), (5, 5, 6), (6,6,6) :}#
Given that the first two rolls are the same:
Similarly
Since these are disjoint occurrences