nguoi ta thu hoach o ba thua ruong duoc 2 tan dua chuot . thua ruong thu nhat tu hoach duoc 1000kg dua chuot thua ruong thu hai thu hoach duoc bang 1/2 so dua chuot cua thua ruong thu nhat . hoi thua ruong thu ba thu hoach duoc bao nhieu ki lo gam dua chuot ?