Răspuns:
Explicație pas cu pas:
2 sticle...............3 bidoane..................19 l
5 sticle................1 bidon........................15 l (inmultim cu 3)
_________
2 sticle...............3 bidoane.........................19 l
15 sticle................3 bidoane.......................45 l
15 - 2 = 13 sticle.......................................45 - 19 = 26 l
1 sticla.........................................................26 : 13 = 2 l
___________
1 bidon...............15 - 5 x 2 = 15 - 10 = 5 l