Question 1144488
For two children in a family, here are the possibilities:<br>

B,B
B,G
G,B
G,G<br>

Since we are told that at least one child is a boy, we can eliminate the fourth choice as a possibility for this family.  Only 1 out of the 3 remaining choices has B,B  so  the probability  for two boys, given that at least one is a boy, is  {{{ highlight (1/3) }}}