Mot can phong hinh chu nhat co chu vi bang 40m. Chieu dai hon chieu rong 4m. Trung binh co 1m nen nha can 10 vien gach hoa de lat . Gia 1 vien gach la 12500 dong . Hoi .
a) Phai dung bao nhieu vien gach hoa de lat kin nen.
b) Tong so tien de lat can phong biet tien cong tho la 200000 dong.