12mere.....10banane ......98lei
6mere.......7banane ........59lei astea ×2 si obt:
12mere......10 banane .....98lei
12mere.......14banane......118
-------------------------'-----------------
________4banane........20lei
1kg banane 20÷4=5lei
6kg mere 59-(7×5)=24lei
1kg mere 24÷6=4lei