Question 1034747
Let's list out the sample space


{1, 1}
{1, 2}
{1, 3}
{1, 4}
{1, 5}
{1, 6}
{2, 1}
{2, 2}
{2, 3}
{2, 4}
{2, 5}
{2, 6}
{3, 1}
{3, 2}
{3, 3}
{3, 4}
{3, 5}
{3, 6}
{4, 1}
{4, 2}
{4, 3}
{4, 4}
{4, 5}
{4, 6}
{5, 1}
{5, 2}
{5, 3}
{5, 4}
{5, 5}
{5, 6}
{6, 1}
{6, 2}
{6, 3}
{6, 4}
{6, 5}
{6, 6}


This is the entire set of possible outcomes. For example, {4, 6} means rolling a 4 first, then a 6 next. 


Often it's handy to write in a table form like you see below. The table makes things more compact and readable. 


<img src = "http://i.stack.imgur.com/9CoBC.gif">
Source: <a href = "http://math.stackexchange.com/questions/598808/if-you-roll-a-fair-six-sided-die-twice-whats-the-probability-that-you-get-the">http://math.stackexchange.com/questions/598808/if-you-roll-a-fair-six-sided-die-twice-whats-the-probability-that-you-get-the</a>


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Now let's focus on the outcomes where the sum of the two rolls gets 9. Those outcomes are...


{3, 6}
{4, 5}
{5, 4}
{6, 3}


Eg: {3,6} means we rolled a 3 first and then a 6. The sum of the roll is 3+6 = 9.


Final Answer: there are <font color=red size=5>4</font> ways to roll a 9