bon ban gop tien mua chung mot chiec may tinh bo tui. ban An gop 1/2 tong so tien cua ba ban khac.ban Bình góp 1/3 tong so tien cua 3 ban khac.ban Cuong gop 1/4 tong so tien cua ba ban khac.con ban Dung gop 15600đ.hoi gia tien cua chiec may tinh bo tui va so tien cua moi nguoi