1 nguoi bo ra 12000000 dong de mua 1 mon hang . Sau khi ban het so hang do; nguoi ta thu duoc ca thay 15600000 dong. Hoi
a, Tien ban hang bang bao nhieu phan tram tien von
b; Tien lai bang bao nhieu phan tram tien von
c;Tien lai bang bao nhieu phan tram tien ban
Giup minh voi mn oi