Răspuns:
Explicație pas cu pas:
17 saci faina .......................12 saci cartofi..................1210 kg
21 saci faina .......................12 saci cartofi..................1410 kg
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4 saci faina ..............................//...................................200 kg
1 sac faina=200:4=50 kg
21 saci faina=21×50=1050 kg
1 sac cartofi=(1410-1050):12=360:12=30 kg