Question

What is a 3 -child family's probability of having two boys given that at least one of their children is a boy?

Answer 1

In three births, these are the possibilities:
BBB
BBG
BGB
BGG
GBB
GBG
GGB
GGG

Answer 2

so it would be 3/8?

Answer 3

If you know that one child is a boy, then you can eliminate GGG

Answer 4

There are 7 possibilities with at least one boy.

Answer 5

There are 4 cases of at least two boys out of 7 cases with at least one boy.

Answer 6

one approach is to do a "map"
equal chance for boy or girl = 1/2
1/2*1/2*1/2 = 1/8 so there are 8 possible outcomes