Find the probability that the sum is as stated when a pair of dice is rolled.

Question

A.4 or 11 or doubles
B. 8,given that the sum is greater than 4.
C.Even,given that the sum is greater than 4.

A. 4 can be obtained by 1&3, 3&1 or 2&2. 11 can only be obtained by 5&6 or 6&5. Doubles are 1&1, 2&2, 3&3, 4&4, 5&5 or 6&6. Since 2&2 occurs in two categories, only use it once to determine probability. Each of these has a 1/36 probability with two die. With "either-or" probabilities, you need to add the probabilities of the individual events.

B. This is confusing. To obtain 8, the sum of the die would always be greater than four. Are the data in error?

If it is 8 or given that the sum is greater than 4, you need to determine the combinations to get 5, 6, 7, 8, 9, 10, 11 or 12 to calculate your probability. Since 8 is in both categories, it only needs to be used once.

C. Assuming that the indivudal die do not need to be even, you need to figure the combinations that give you 6, 8, 10 and 12 to calculate the total probability from there.

I hope this helps. Thanks for asking.