SOLUTION: Your teacher chooses 2 students at random to represent your homeroom. The homeroom has a total of 30 students, including your best friend. What is the probability that you and your

Algebra ->  Permutations -> SOLUTION: Your teacher chooses 2 students at random to represent your homeroom. The homeroom has a total of 30 students, including your best friend. What is the probability that you and your      Log On


   

Question 730731: Your teacher chooses 2 students at random to represent your homeroom. The homeroom has a total of 30 students, including your best friend. What is the probability that you and your best friend are chosen?
Found 3 solutions by lynnlo, ikleyn, greenestamps:
Answer by lynnlo(4176) About Me  (Show Source):
Answer by ikleyn(53411) About Me  (Show Source):
You can put this solution on YOUR website!
.
Your teacher chooses 2 students at random to represent your homeroom.
The homeroom has a total of 30 students, including your best friend.
What is the probability that you and your best friend are chosen?
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The total number of different pairs is  %2830%2A29%29%2F2 = 435  (the order does not matter).


There is only one preferable pair: you and your best friend (the order does not matter).


Therefore, the probability of this happy case is  1%2F435.    ANSWER

Solved.

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The answer in the post by @lynnlo is incorrect.
So and therefore, ignore his post.



Answer by greenestamps(13257) About Me  (Show Source):
You can put this solution on YOUR website!


For tutor @ikleyn....

You are missing an open parentheses where you show the calculation for the total number of possible combinations, resulting in the statement "30*29=435".

You probably want to clean that up so the student is not confused.