三中三的概率怎么算.

买三中三概率:
C(6,3)/C(49,3)=6*5*4/(49*48*47)=5/(49*2*47)=5/4606≈0.0011
买三中二概率:
C(6,2)*C(43,1)/C(49,3)=15*43*1*2*3/(49*48*47)=645/18424≈0.0350
买三中一概率:
C(6,1)*C(43,2)/C(49,3)=6*43*21*1*2*3/(49*48*47)=2709/9212≈0.2941
买三全不中概率:
C(43,3)/C(49,3)=43*42*41/(49*48*47)=43*41/(7*8*47)=1763/2632≈0.6698