Respuesta :

[tex]\bf \cfrac{\stackrel{first}{group}}{\stackrel{second}{group}}\qquad 3:5\qquad \cfrac{3}{5}\implies \cfrac{3\cdot \frac{72}{3+5}}{5\cdot \frac{72}{3+5}}\implies \cfrac{3\cdot 9}{5\cdot 9}\implies \cfrac{27}{45}[/tex]