Se rezolvă prin metoda comparației:
7d ...................................6b..................................190 l / x 2
14d ..................................5b.................................. 240l
14d .................................12b..................................380 l se scad
14d ...................................5b.................................. 240 l
____________________________________________
/ 7b ..................................140l
b = 140 : 7
b = 20l
7d + 6b = 190 l
7d + 6 x 20 = 190 l
7d + 120 = 190 l
7d = 190 - 120
7d = 70
d = 70 : 7
d = 10 l
V: 7 x 10 + 6 x 20 = 70 + 120 = 190 l