0
1/12
1/6
1/4
F(0,1/3)=P{X≤0,Y≤1/3}=P{X=-1,Y=0}+P{X=0,Y=0}+P{X=-1,Y=1/3}+P{X=0,Y=1/3}=0+1/6+1/12+0=1/4
答案为D