Question 245300
There are 100 students that are randomly placed into 4 classrooms. 
Three students want to be in the same class.
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Probability they are in the same class? 
Pick a classroom: 4 ways
Place the 3 randomly: 100*99*98 ways
Probability 4/(100*99*98) = 0.000004123
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probability they are all  in P's class?
# of ways to succeed: 1 way
# of ways to place randomly: 100*99*98
Probability = 1/970200
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Probability they are all in different classes?
Pick 3 classes: 4C3 = 4
Put the 3 students in the three classes: 3*2*1 = 6
probability (4*6)/970200 = 0.00002474
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Cheers,
Stan H.