Question 697712
Your drawer contains 8 red socks and 9 blue socks.  It’s too dark to see which are which, but you grab two anyway.  What is the probability that you get one of each color?
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Another way:

P[(red 1st AND red 2nd)  OR  (blue 1st AND red 2nd)]

AND means multiply and OR means add:

P(red 1st)×P(red 2nd) +  P(blue 1st)×P(red 2nd)] =

{{{8/17}}}×{{{7/16}}} + {{{9/17}}}×{{{8/16}}} = 

{{{cross(8)/17}}}×{{{matrix(2,1,"",7/(cross(16))[2])}}} + {{{9/17}}}×{{{matrix(2,1,"",cross(8)/(cross(16))[2])}}} =

{{{7/34}}} + {{{9/34}}} = {{{16/34}}} = {{{8/17}}}

Edwin</pre>