Tong cua 4 so tu nhien la so lon nhat co hai chu so .Neu xoa di chu so o hang don vi cua so thu nhat thi duoc so thu hai .So thu ba = hieu cua so thu nhat va so thu hai .So thu nhat la tich cua so be nhat co ba chu so va so co bon chu so .Tim so thu tu .
 

Tong cua bon so tu nhien la so lon nhat co bay chu so. Neu xoa di chu so hang don vi cua so thu nhat thi duoc so thu hai. So thu ba bang hieu cua so thu nhat va so thu hai. So thu nhat la tich cua so be nhat co ba chu so va so lon nhat co bon chu so. Tim so thu tu.

Tong 4 so la 2192 xoa chu so hang don vi so 1 ta duoc so 2 xoa chu so hang don vi so 2 ta duoc so 3 xoa chu so hang don vi so 3 ta duoc so 4 ,tim so thu nhat

1.Cho so N la so co hai chu so chia het cho 3.Neu viet xen so 0 vao giua hai chu so do roi cong no voi hai lan chu so hang chuc cua so N ta duoc so moi gap 9 lan so N.Tim so do

2.Tong hai so thap phan la 60,1.Neu dich dau phay cua so nho sang ben phai mot hang roi dem tru di so lon thi ta duoc 219,52.Tim hai so do.

3.Tim so co hai chu so biet neu ta them so 33 vao giua hai chu so do thi duoc mot so moi gap so phai tim 89 lan.

cho so co 2 chu so ma so lon bang 3 lan so be. neu dem so be viet them vao ben phai va ben trai so lon ta duoc hai so moi moi so 4 co 4 chu so. tong cua 2 so co 4 chu so do bang 4848. tim 2 so  da cho

tong cua 2 so  bang so lon nhat co 4 chu so. ti so giua hai so lon va so be bang so nho nhat co 2 chu so .tim hai so do

tong cua hai so bang so lon nhat co 4 chu so .ti so giua so lon va so be bang so be nhat co hai chu so . em hay tim hai so do

Tim 2 so, biet so lon gap 9 lan so be va so lon la so co ba chu so voi chu so hang tram la 4, dong thoi neu xoa di chu so hang tram cua so lon thi duoc so be

Tim so co 4 chu so biet so do cong voi so co 2 chu so tao boi chu so hang nghìn ,tram va so co 2 chu so tao boi chu so hang chuc ,don vi cua so do tong la 7968