SOLUTION: Assume that each child that is born is equally likely to be a boy or girl . If a family has two children what is the probability that 1) both are girls 2) Elder is girl 3) fi

The total space of events is presented by this table, where all 4 (four) possibilities are listed (B=boy;  G=girl)


    older    younger    Probability

      B         B          1/4

      B         G          1/4

      G         B          1/4

      G         G          1/4


To answer questions, you simply count, how many favorable cases you see in the table, 
and then relate this number to the total number of all possible cases, which is 4.


1)  P = 


2)  P =  = 


3)  P = 


4)  P =    (at least two boys means "two boys", in this case)


5)  P =  =