An ordinary (fair) die is a cube with the numbers
1 through 6 on the sides (represented by painted spots). Imagine that such a die is rolled twice in succession and that the face values of the two rolls are added together. This sum is recorded as the outcome of a single trial of a random experiment.
Compute the probability of each of the following events:
Event A: The sum is greater than 8.
Event B: The sum is divisible by 3 or 5 (or both).

Question

An ordinary (fair) die is a cube with the numbers 
1 through 6 on the sides (represented by painted spots). Imagine that such a die is rolled twice in succession and that the face values of the two rolls are added together. This sum is recorded as the outcome of a single trial of a random experiment.
Compute the probability of each of the following events:
Event A: The sum is greater than 8.
Event B: The sum is divisible by 3 or 5 (or both).

mhchen · Answer

First of all, make a table of the sample space (Possible outcomes). Each probability has a 1/36 chance right? Add up all the outcomes with a sum greater than 8 for Event (A). And do the same method for Event (B). http://bestcase.files.wordpress.com/2011/01/dicediagram.jpg