1.
P(3 different)=P(RYB)+P(RBY)
+P(YRB)+P(YBR)+P(BYR)+P(BRY)
=63(62)(83)+63(62)(84)+62(62)(83)
+62(62)(81)+61(62)(81)+61(62)(84)
=7217
2.
The first test must be negative
P(Negative)=55−1 The second test must be positive
P(Positive)=5−11 Then
P(X=2)=P(1stNegative,2ndPosirive)
=55−1(5−11)=51
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