设二维随机变量(X,Y)的分布律为 XY012 01/122/122/12 11/121/120 22/121/122/12 则

设二维随机变量(X,Y)的分布律为
XY012
01/122/122/12
11/121/120
22/121/122/12
则P{XY=0}=____.
A、1/12
B、2/12
C、4/12
D、8/12
【正确答案】:D
【题目解析】:P{XY=0}=P{X=0}+P{Y=0}-P{X=0,Y=0} =1/12+2/12+2/12+1/12+1/12+2/12-1/12=8/12