[tex]b-boys\\g-girls\\\\\frac{b}{g}=\frac{2}{3}\to b=\frac{2}{3}g\\\\b+g=120\to\frac{2}{3}g+g=120\\\\\frac{2}{3}g+\frac{3}{3}g=120\\\\\frac{5}{3}g=120\ \ \ \ \ /\cdot\frac{3}{5}\\\\g=72\\\\b=\frac{2}{3}\cdot72=2\cdot24=48\\\\Answer:48\ boys\ and\ 72\ girls.[/tex]