25 kg mere...............307,5 lei
18 kg mere.................X lei
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25X=307,5x18
25X=5535
X=5535:25
X=221,4 lei (atat vor costa 18 kg mere)
17 kg pere.........374 lei
20kg pere........X lei
_____________________
17X=374x20
17X=7480
X=7480:17
X=440 lei (atat vor costa perele)
221,4+440=661,4 lei