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3-66.

A player in the casino dice game described in Roll and Win (problem 3-6) rolled a sum of six on his first roll.  He will win if he rolls a sum of six on the second roll but lose if he rolls a sum of seven.  If anything else happens, the result is ignored and he gets to roll again.  3-66 HW eTool (CPM)  Homework Help ✎

1. How many ways are there to get a sum of six?

Refer to the table.

2. How many ways are there to get a sum of seven?

Refer to the table.

6 ways

3. How many possible outcomes are important in this problem?

How many ways are there to roll a sum of 6 or a sum of 7?

4. What is the probability of getting a sum of six before a sum of seven?

$\frac{\text{# of ways to get a sum of six}}{\text{total of important possible outcomes}}$

Insert the sums into the table in the eTool below to help you find the probabilities in parts (a) - (d).
Click the link at right for the full version of the eTool: Int2 3-66 HW eTool