luc dau thung thu nhat nhieu hon thung thu hai la 5 lit dau.nguoi ta da ban di 10 lit dau o thung thu hai va 5 lit dau o thung thu nhat.luc nay so lit dau o thung thu hai bang 3/5 so lit dau o thung thu nhat.hoi luc dau moi thung co bao nhieu lit dau?