Probability again
posted by Ryan on .
A box contains 6 red balls, 4 blue balls, and 2 green balls. Three balls are randomly drawn (without replacement) from the box. What is the probability that the three balls selected are all the same color?

follow the basic methodology that Drwls showed you in the previous post. Assume each color ball can be distinguished from each other. (e.g., name the green balls g1 and g2) First, the denominator. How many different ways can 3 balls from 12 be chosen. 12choose3 is 12!/3!(123)!
Now the numerator. How many different ways can 3 red balls be chosen from 6? Plus how many different ways can 3 blue balls be chosen from 4.
Take it from here. 
im lost

A bag contains 5 yellow balls, 5 orange balls, 6 white balls and 6 red balls. Five balls are drawn and NOT replaced each time