Joe M. answered 05/29/19
Probability Tutor and College Professor with 10 Years Experience
Hi Jess,
The probability of getting a blue chip on the first draw is 5/12 since 5 of the 12 chips are blue. Then there are 11 chips left and 4 are red so that probability is 4/11. This combined probability is 5/12 * 4/11 = 5/33.
The other possibility is that a red chip is drawn first, which is 4/12, and then a blue chip is drawn which is 5/11. This combined probability is 4/12 * 5/11 = 5/33.
The total probability of one of these events happening is then 5/33 + 5/33 = 10/33.
Please let me know if I can be more helpful, thanks!
Joe