a+b+c = 879
a = 3×b+25
c = a+b+29
a |___|___|___|+25
b |___|
c |___|___|___|___|+25+29
avem 8 segmente egale +25+25+29 = 879
879-(25+25+29) = 879-79 = 800
800 : 8 = 100 ( un segment)
a = 3×100+25 = 300+25 = 325
b = 100
c = 4×100+54 = 400+54 = 454
Verificare:
325+100+454 = 879
325 probleme a rezolvat primul elev
100 probleme a rezolvat al 2-lea elev
454 probleme a rezolvat al 3-lea elev