当划右桨的全部从3个只会右桨的人中选,有C(3,3)*C(8,3)=336种当划右桨的有一个为两种都会时:C(3,2)*C(4,1)*C(7,3)=420种当划右桨的有两个为两种都会时:C(3,1)*C(4,2)*C(6,3)=360种当右桨的全部为两种都会时:C(4,3)*C(5,3)=40种共336+420+360+40=1156种
77