Question 1081849
expression 1 = ₉C₃
expression 2 = ₂₀C₃

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expression 1:   ₉C₃ = 9!/(6!*3!) = (9*8*7)/(3*2) = 84
expression 2:  ₂₀C₃ = 20!/(17!*3!) = (20*19*18)/(3*2) = 1140