概率论中C(8,3)除以C(10,3)怎么算
问题描述：
概率论中C(8,3)除以C(10,3)怎么算
答
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
答
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
答
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
答
=（8×7×6/3×2×1）/（10×9×8/3×2×1×）=8×7×6/10×9×8=7/15。