概率论中C(8,3)除以C(10,3)怎么算

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概率论中C(8,3)除以C(10,3)怎么算概率论中C(8,3)除以C(10,3)怎么算概率论中C(8,3)除以C(10,3)怎么算C(m,n)=m!/[(m-n)!n!]C(8,3)=8!/(5!3

概率论中C(8,3)除以C(10,3)怎么算
概率论中C(8,3)除以C(10,3)怎么算

概率论中C(8,3)除以C(10,3)怎么算
C(m,n)=m!/[(m-n)!n!]
C(8,3)=8!/(5!3!)
C(10,3)=10!/(7!3!)
C(8,3)/C(10,3)=[8!/(5!3!)]/[10!/(7!3!)]=(8!7!3!)/(10!5!3!)=(7×6)/(10×9)=7/15

=(8×7×6/3×2×1)/(10×9×8/3×2×1×)=8×7×6/10×9×8=7/15。

C(8,3)=8!/(3!5!)=8*7*6/(3*2)=56
C(10,3)=10!/(3!7!)=10*9*8/(3*2)=120
C(8,3)/C(10,3)=56/120=7/15

C(8,3)=8*7*6/3*2*1=56
C(10,3)=10*9*8/3*2*1=120
C(8,3)/C(10,3)=56/120=7/15