# Math (probability)

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Three members of a 12 person singing group are going to be chosen to sing a song in their coming concert.

A) how many different groups containing 3 people can be chosen from the 12 members of the singing group?

B) what Is the probability that mike and Jo will both be in the selected group?

• Math (probability) -

b. three choices
?MJ
?JM
J?M
JM?
MJ?
M?J so there are six ways to get it, so probability is 6*(1/12*1/11*10/10)

a. 3!/12!9!

• Math (probability) -

oops a. 12!/(3!9!)=12*11*10/6=11*10*2
check that

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