Question

Irina, Sabina si Larisa au impreuna 59 lei. Sabina are de 2 ori mai mult decat Irina si cu 9 lei mai putin decat Larisa . Cati lei are fiecare?

Answer 1

i+s+l=59
s=2i=>i=s/2
s=l-9=>l=s+9
s/2+s+s+9=59 I x2
s+2s+2s+18=118
5s=118-18=>s=100:5=>s=20 lei are Sabina
i=20:2=10 lei are Irina
l=20+5=29 lei are Larisa