00:01
This problem says we buy a bag of cookies that contains five chocolate chip cookies, eight peanut butter cookies, seven sugar cookies, and five oatmeal cookies.
00:08
What's the probability that we reach in the bag and randomly select a chocolate chip cookie from the bag, eat it, and then reach back into the bag and randomly select a peanut butter cookie? give your answer as a fraction or accurate to at least four decimal places.
00:20
So for this probability, we need to look at these two events separately first and find the probability of them individually, and then multiply those probabilities together to figure out the probability that both would occur.
00:30
So just focused on reaching in and picking one of the chocolate chip cookies, we need to know the total number that's in the bag, and five plus eight plus seven plus five tells us that there are 25 total in the bag.
00:43
So again, just looking at the probability of the first action, we have five chocolate chip cookies total that are possible out of the total 25 in the bag, and we will now multiply that by the probability of us getting a peanut butter one after we eat the chocolate one.
00:59
And what we need to keep in mind here is that once we selected this chocolate cookie, a chocolate chip cookie, we ate it...