SOLUTION: How do I solve this problem? Please explain step by step. Thanks so much! A box of cookies contains 4 chocolate and 6 butter cookies. Miguel randomly selects a cookie and eats

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Question 1167279: How do I solve this problem? Please explain step by step. Thanks so much!

A box of cookies contains 4 chocolate and 6 butter cookies. Miguel randomly selects a cookie and eats it. Then he randomly selects another cookie and eats it. (How many cookies did he take?)
P(BB) = 30/90
P(BC) = 24/90
P(CB) = 24/90
P(CC) = 12/90

Let T be the event that both cookies selected were different flavors.
Find P(T). Use the complement rule and the branches of the tree. The answers should be the same with both methods. (Enter your probability as a fraction.)
Answer by ikleyn(52915) (Show Source):
You can put this solution on YOUR website!
A box of cookies contains 4 chocolate and 6 butter cookies. Miguel randomly selects a cookie and eats it. Then he randomly selects another cookie and eats it. (How many cookies did he take?)
P(BB) = 30/90
P(BC) = 24/90
P(CB) = 24/90
P(CC) = 12/90

Let T be the event that both cookies selected were different flavors.
Find P(T). Use the complement rule and the branches of the tree. The answers should be the same with both methods. (Enter your probability as a fraction.)
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Your calculations for the first question are correct.

To answer the second question, add P(BC) and P(CB).

You do not need their instruction.
Their instruction is INCORRECT and IRRELEVANT to this problem.
I suspect that this instruction came to this post by mistake from another problem.

Do not be surprised: at this forum, such events happen every day, and even several times per day.
It says a lot about the responsibility of visitors who post to this forum.