Răspuns:
6vaci....... 15 oi.... 180 kg
3 vaci..... 15 oi..... 150kg-30kg=120kg
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3vaci.....................60kg
O vaca consuma 60kg:3=20kg
6x20kg+15oi.......180kg
120kg.....15 oi...... 180kg
15 oi consuma 180kg-120kg
15 oi consuma 60kg
O oaie consuma 60kg:15
O oaie consuma 4kg fan
120kg+60kg=180kg
60kg+60kg=120kg