Fie T = totalul de bile
Notam : bile rosii = r
bile albe = a
bile negre = n
Avem :
r = [tex] \frac{3}{6} * T[/tex]
a= [tex] \frac{5}{8} * ( \frac{3}{6}*T )[/tex]
n = 9
T = r + a + n
T = [tex] \frac{3}{6} * T[/tex] + [tex] \frac{5}{8} * ( \frac{3}{6}*T )[/tex] + 9
T= [tex] \frac{8T + 5T + 144}{16} [/tex]
16T = 8T + 5T + 144
16T - 13T = 144
3T = 144 ⇒ T = 48 (totalul de bile din cutie)
