Jelly beans problem

Question

You have a jar of 12 jelly beans. There are 4 each of red, green and white. If you cannot see the colors inside the jar, how many jelly beans do you need to take out before you can be sure you have at least one red?

Answer 1

You would have to take out at least 9 jelly beans to make sure you had a red one. The reason is because you could pick 4 green, 4 white (4 + 4 = 8) and then the 9th one would have to be red, because you have exhausted all of the white and green jelly beans. You may get a red before you take out 9, but to be sure, you would need to pick 9 jelly beans.

Answer 2

You'd have to take out 4+4=84+4=8 jelly beans (4 green + 4 white) before being certain you've got at least one red jelly bean.