Question 1010864
I know the equation is something like 20C2/26C2, but i do not know what "C2" stands for. 
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20C2 is the number of pairs you get from 20 distinct objects.
26C2 is similar.
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20C2 = (20*19)/(1*2) = 190
26C2 = (26*25)/(1*2) = 13*25
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Cheers,
Stan H.
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