Question 1074739
w, wife
b, first born child
h, husband


{{{system(w=2b,w=h-5,w+b+h=100)}}}


Put b and h in terms of w.
{{{system(b=w/2,h=w+5)}}}


Substitute into sum of ages.
{{{w+w/2+w+5=100}}}
Solve for w; and then continue...