cau 1 ;2 so co tong la 346 biet so be la so co hai chu so va khi viet them chu so 3 vao truoc so be thi duoc so lon tim so be
cau 2 ; tong 2 so la 390 so be l¸o co 2 chu so va neu viet them chu so 3 vao truoc so be thi duoc so lon tim so lon
cau3;chu vi 1 khu dat hinh chu nhat =68 chieu dai hon chieu rong16m nguoi ta trong rau tren khu dat do TB cu 2m vuong trong duoc 2 kg rau tinh so rau o khu dat do
cau4 ; TBCcua 2 so la so nho nhat co 3chu so khac nhau biet so lon lon hon TBCcua 2so la 24 don vi tim so be va so lon
