Question 1161556: There are 10 red jelly beans, 8 blue jelly beans, and 12 white jelly beans in a jar, and you pick out three jelly beans, one at a time, without replacement. What is the probability that they are all blue?
Found 2 solutions by ikleyn, greenestamps:
Answer by ikleyn(52780)   (Show Source):
You can put this solution on YOUR website! .
There are 10+8+12 = 30 jelly beans, in all.
Therefore, the probability under the question is
P =  = 0.013793. ANSWER
The formula is self-explanatory.
Solved.
Answer by greenestamps(13200)  (Show Source):
You can put this solution on YOUR website!
Calculating the probability by the "one at a time" method shown by tutor @ikleyn is something you should know how to do.
There is another basic combinatorics method you should also know that can be used to solve the problem.
Out of the 30 total jelly beans, you need to pick 3; and you want to get 3 of the 8 blue, 0 of the 10 red, and 0 of the 12 white:
= 
= 0.013793 to several decimal places
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