a+b+c=440
a-80a/100=a-4a/5=a/5
b-3b/4=b/4
c-c/2=c/2
a/5=b/4=c/2
b=4a/5
c=2a/5
a+4a/5+2a/5=440
5a+4a+2a=2200
11a=2200
sume initiale
a=200 lei
b=4*200/5=160 lei
c=2*200/5=80
sume cheltuite de fiecare copil
copil 1 200 *80%=160 lei
copil 2 160*3/4=120 lei
copil 3 80:2=40 lei