Need help with probability problems.

[slackerinabox]

Now this example is just pulled out of nowhere - I just want to know how to solve these type of problems:

Bob sells cars.. He has 2 red ones, 2 black ones, 8 orange ones, and 4 gray ones.. Assuming that once a car is sold it's not replaced, what's the probability of selling an orange one first and then a 2 gray ones...

 

[Muzzan]

I believe you figure out the probability for all the events by them self, and then multiply them together.

Prob. for selling an orange car = 8/16, prob. for selling a gray car (remember, he's already sold a car, so there's a total of 15 cars left) = 4/15, prob. for selling another gray car = 3/14.

In this case, P = 8/16 * 4/15 * 3/14 = 96/3360 = 1/35.

 

[Orsorum]

Essentially. Without replacement, it is as he stated. You account for the total number in the population as ones are withdrawn (or not, if there is replacement)

 

[slackerinabox]

Thanks guys! I knew it was simple but the text book explains everything in such a round about way (the writers get paid per word )