Răspuns :
sc. 1 = a; sc2 = b; sc3 = c
a=b-270
c=143+a
b=341 =>a=341-270=71 kg
c=143+71=214 kg
Total = 341 + 71 + 214 = 626 kg.
341-270=71kg hartie( prima scoala)
71+143=214 kg hartie( a treia scoala)
71+341+214=626kg hartie( in total )
71+143=214 kg hartie( a treia scoala)
71+341+214=626kg hartie( in total )