Answer:
The possible cases of the children in increasing order of age are
1) Boy,Boy,Girl
2)Boy,Girl,Boy
3)Girl,Boy,Boy
4)Girl,Girl,Boy
5)Girl,Boy,Girl
6)Boy,Girl,Girl
The favorable cases in our event are 2 numbered 4 and 5
Thus the required probability is
[tex]P(E)=\frac{2}{6}\\\\P(E)=\frac{1}{3}[/tex]