1) Ban Xuan mua sach toan va sach van het 70 500 dong . Ban Ha mua sach toan va sach van het 64 500 dong . Biet moi quyen sach toan gia 7 500 dong , sach van gia 6 000 dong va so sach toan ban cua ban nay so sach van cua ban kia . Hoi ban Xuan mua bao nhieu sach toan , bao nhieu sach van ?
2) Hai nguoi cung lam chung 1 cong viec sau 12 gio thi hoan thanh . Neu nguoi thu nhat lam mot minh 2/3 cong viec mat 10 gio . Hoi nguoi thu hai lam 1/3 thi het bao lau moi xong ?
Cac ban giai duoc bai nao thi giai nhe !