$\displaystyle P(\text{2 boys, 2 girls})=\frac{6}{16}$ I agree with that.Couple are planning four kids. What is more likely: both genders equal (2 boys, 2 girls)or3 of one gender and 1 of the other gender?

But is $\displaystyle P(\text{3 boys, 1 girl or vice-versa})$ really $\displaystyle \frac{8}{16}$? I'd say it is rather $\displaystyle \frac{{4\choose 1}}{16}=\frac{4}{16}$.

How could they get $\displaystyle 8$ in the numerator?!

Is there already any [tex] keyboard shortcut? I vote for FN/CTRL+M.