Notez cu n numarul de probleme
2/7*n - prima saptamana
3/5*n - a doua saptamana
16- a treia saptamana
2/7*n+3/5*n+16=n
Aducem la numitorul comun (35)
2*5n+3*7n+16*35=35n
10n+21n+560=35n
31n+560=35n
560=4n
n= 560/4=140
2/7*140= 2*20=40 probleme prima saptamana
3/5*140=3*28= 84 probleme a doua saptamana
