<PRE><B>Question 163920</B>
A group of 3 students is to be selected from a group of 12 students to take part in a class in cell biology.
a) in how many ways can this be done?
Ans: 12C3 = [12*11*10]/[1*2*3] = 220
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b) in how many ways can the group who will not take part be chosen?
Ans: the answer is the same because for each group that is chosen
there is a group that is not chosen.
So 12C3 = 12C9
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Cheers,
Stan H.
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