Răspuns :
notam cu:
a= nr.meri
b=nr.peri
c=nr.pruni
a+b+c=1560
a=b+180
c=a-30 , inlocuim pe a si c
b+180+b+b+180-30=1560 => 3b+330=1560 => b=(1560-330)/3=410 peri
a=b+180=410+180=590 meri
c=a-30=590-30=560 pruni
a= nr.meri
b=nr.peri
c=nr.pruni
a+b+c=1560
a=b+180
c=a-30 , inlocuim pe a si c
b+180+b+b+180-30=1560 => 3b+330=1560 => b=(1560-330)/3=410 peri
a=b+180=410+180=590 meri
c=a-30=590-30=560 pruni
a=mere
b=pere
c=prune
a+b+c=1560
a=b+180
c=a-30
a+b+c=1560
b+180+b+a-30=1560
b+180+b+b+180-30=1560
3b+330=1560
3b=1560-330
3b=1230
b=1230:3=410 de pere
a=b+180=410+180=590 de mere
c=a-30=590-30=560 de prune
proba 410+590+560=1560
b=pere
c=prune
a+b+c=1560
a=b+180
c=a-30
a+b+c=1560
b+180+b+a-30=1560
b+180+b+b+180-30=1560
3b+330=1560
3b=1560-330
3b=1230
b=1230:3=410 de pere
a=b+180=410+180=590 de mere
c=a-30=590-30=560 de prune
proba 410+590+560=1560