Question 746351
<pre>
Probability = {{{Number_of_successful_choices/Number_of_possible_choices}}}

The successful numbers are these 4: {9,10,11,12}
The possible numbers are these 12: {1,2,3,4,5,6,7,8,9,10,11,12}

The number of successful choices are "4 things choose 2", or C(4,2) = {{{4*3/(2*1)}}} = 6

The number of possible choices are "12 things choose 2", or C(12,2) = {{{12*11/(2*1)}}} = 66

Probability = {{{Number_of_successful_choices/Number_of_possible_choices}}} = {{{6/66}}} = {{{1/11}}}

Edwin</pre>