bai1:Mot khu rung hinh chu nhat co chieu dai 3km va chieu rong 2km.Hoi dien tich cua khu rung do bang bao nhieu ki-lo-met vuong?
bai2:mot cua hang nhan ve 186 thung banh, moi thung chua 72 goi banh.Neu tat ca so banh do xep vao cac thung, moi thung dung 120 goi thi can bao nhieu thung de xep het so banh do?
bai3:
a} 240000:80:125 b} {24500-490}:245 c} 750000:{ 25*125}