Raina places the following balls into a bag. She draws three balls out of the bag, one at a time, without replacement. What is the probability that the colors of the balls alternate?
There are 6 orange balls and 6 purple balls.
This link might help:
https://www.quora.com/Three-balls-are-drawn-without-replacement-from-a-bag-containing-3-black-5-purple-and-6-yellow-balls-Given-that-the-drawn-balls-are-all-the-same-colour-what-is-the-probability-they-are-purple