Question

跪求大神解答一道概率论题！！！袋内有四张卡片,分别写有数字1,2,3,4,用放回抽样方式先后从袋中抽出两张,

Answer 1

当敬昌卜
X等于Y且属于{1,2,3,4}时，
P(X,Y)
=
1/16
...
两次都摸到X,
(1/4)*(1/4)
当
X不等于Y且X属于{1,2,3,4}且Y属于{1,2,3,4}时，
P(X,Y)
=
1/8
...
先摸X后摸Y或先迅信摸Y后摸X，
(1/4)*(1/4)
+
(1/4)*(1/4)
当X或Y不属于{1,2,3,4}时，
P(X,Y)
=
0
...
没有的牌摸不出来亮穗