00:01
Okay, so having read your problem, we first have to make a sample space, which is basically just making an organized list of all possible outcomes.
00:11
So if you're going to pick two pencils, what could happen? they could both be green, so i wrote gg.
00:19
The first one could be green in the second magenta, so i wrote gm.
00:23
The first one could be green in the second yellow, so i wrote gy.
00:27
Or you could get magenta green, magenta, magenta.
00:30
Magenta yellow, yellow green, yellow magenta, or yellow yellow, yellow.
00:36
So there are nine possible outcomes in the sample space.
00:40
So unfortunately, that means that there are nine probabilities that must be calculated in the second part of this problem, using correct notation.
00:51
So for example, let's say that i need to find the probability that both pencils are green.
00:57
So i wrote, what is the probability the first is green and the second? is green.
01:02
Well, if your teacher or professor insists on proper notation, you say that that's equal to the probability that the first one is green, multiplied by the probability that the second one is green, given that the first one is green.
01:19
That little slash represents given that.
01:24
And i know this notation seems complicated, but it's not.
01:28
Listen to my voice and just be logical.
01:31
What is the probability that the first draw is green? well, that would be 8 out of 25 times.
01:42
Now, just listen...