Notam : cant ridichi prim ladita =a
cand ridichi a2a ladita= b
cand ridichi a3a ladita= c
a+b+c=110
a+b=66
b+c=81
Adunam ultimele 2 ecuatii si obtinem; a+b+b+c= 66+81
a+2b+c= 147
Aflam cate ridichi sunt in plus: 147 -110= 37 ⇒ b=37 kg
a= 66-37 =29 kg
c= 81-37=44kg
Proba: 29+44+37 =110 (adevarat)