1)total bani=720 lei
rochie=4/9
4/9=720:9x4
4/9=40x4=320 lei costa rochia
pantofi=2/6
720:6x2=
120x2=240 lei costa pantofii
240-190=50 lei costa cerceii
2)504 prajituri
4/7=504:7x4
72x4=288 vandute dimineata
504-288=216 ramase
216:8x5=
27x5=135 vandute dupa amiaza
504-288-135=81 prajituri ramase
3)560 km total
2/7=560:7x2=
80x2=160
160+30=190km prima zi
560-190=370 km ramasi
3/10=370:10x3=
37x3=111 km a doua zi
190+111=301(1+2)
560-301=259 km in a treia zi
