【俊狼猎英】团队为您解答~PX,PY,PXY,PM分别表示x,y,x和y,max(x,y)>=0的概率PM=1-P{X<0,Y<0}P{X<0,Y<0}=1-PXY-P{X>=0,Y<0}-P{X<0,Y>=0}P{X>=0,Y<0}=PX-PXY=1/7P{X<0,Y>=0}=PY-PXY=1/7从而P{X<0,Y<0}=1-3/7-1/7-1/7=2/7PM=1-2/7=5/7