Question 162666
See this video for a nice look at this type of problem. http://collabvsl.wetpaint.com/page/Basic+Probability

In this case, you have a total of {{{5+3+1}}}={{{9}}} marbles.
The odds of drawing a blue marble are {{{3/9}}} = {{{1/3}}}
So the odds of drawing a 'non-blue marble is {{{1 - (1/3)}}} = {{{2/3}}}