Question 1148783
g, Gabriela (current age)
b, Brother (current age)
{{{system(g=b/2,g-4=(1/3)(b-4))}}}


{{{b/2-4=(1/3)(b-4)}}}

{{{6(b/2-4)=6(1/3)(b-4)}}}

{{{3b-24=2(b-4)}}}

{{{b=24-8}}}

{{{highlight(b=16)}}}-----------------The brother's CURRENT age.