b numarul baietilor
f numarul fetelor
Avem
[tex] \left \{ {{b=2f} \atop {b-2= \frac{120}{100}.(f+5) }} \right. \\ \left \{ {{b=2f} \atop {2f-2=1,2f+6}} \right. \\ \left \{ {{b=2f} \atop {0,8f=8}} \right. \\ \left \{ {{f=10} \atop {b=20}} \right. [/tex]
30 de elevi
