Andrei,Mihai si Cosmin colectioneaza timbre.Mihai are de trei ori mai multe timbre decat Andrei,iar Cosmin are de doua ori mai multe timbre decat Mihai.In total baietii au 90 de timbre.Cate timbre are fiecare?
Notezi :
t-timbre are Andrei
3t-timbre are Mihai
6t-timbre are Cosmin
Le adunam->10t=90->t=9
Deci Andrei are 9 timbre,Mhai are 27 iar Cosmin are 54.