math
posted by juan777 on .
A couple intends to have four children. Assume that having a boy and girl is equally likely event.
a) List sample space
b) Find the probability that couple has two boys and two girls;
c) Find the probability that couple has at least one boy

finish the chart
BBBB
BBBG
BBGB
BBGG
.....
GGGG  you should have 16 of these
count the number of cases for each of your events,
then divide by 16 to the prob. 
5. A couple plans to have 3 children. Find the possible ways the couple can have 3 children.
 1a3b+3a2b1+3a1b2+1 a0b3
1a3= 1 case with boy, boy, boy
3a2b1= 3 cases with 2 boys and a girl
3a1b2=3 cases with a boy and 2 girls
1b3= 1 case of girl, girl and girl. 
12345