SOLUTION: In a class of 10 children, what is the probability that 2 friends will be chosen to go on a trip. Only 2 will be chosen.

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Question 784471: In a class of 10 children, what is the probability that 2 friends will be chosen to go on a trip.
Only 2 will be chosen.

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
10C2=n!/(r!(n-r!))
=10!/(2!*8!)
=10*9*8!/8!*2
=10*9/2
=45
There are 45 ways to choose 10 children 2 at a time so the probability that the two friends will be chosen to go is 1/45.
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Ed