Question

Justin buys a bag of cookies that contains 7 chocolate chip cookies, 9 peanut butter cookies, 8 sugarcookies and 8 oatmeal cookies. What is the probability that Justin randomly selects a peanut buttercookie from the bag, eats it, then randomly selects an oatmeal cookie? Express you answer as areduced fraction.

Answer 1

7 choco chip

9 peanut butter

8 sugar

8 oatmeal

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total = 32 cookies

We want probabilty of selecting peanut butter and then oatmeal (given he eats the peanut butter).

Prob of peanut butter is 9/32

Then,

we are left with 31 cookies (since ate 1)

we still have 8 oatmeal, so

Prob of oatmeal 8/31

Now we mutliply:

`(8)/(31)*(9)/(32)=(9)/(124)`

This is the final answer, reduced. (9/124)