Cho 1 so co 2 chu so,biet rang neu viet them 1 chu so 0 xen giua 2 chu so cua 1 so do thi duoc so co 3 chu so gap 9 lan 2 chu so dau
cho so 97531 .Viet them chu so 8 xen giua cac chu so cua so do de duoc so
a. lon nhat
b . bé nhất
tim 1 so co 2 chu so biet rang khi viet them chu so 0 vao giua 2 chu so cua so do thi duoc so moi gap 7 lan so da cho
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.
tim 1 so co 2 chu so biet rang khi viet them chu so 0 vao giua 2 chu so cua so do thi duoc so moi gap 6 lan so da choedt
tim 1so co 2 chu so biet so do chia het cho 9 . neu viet them chu so 0 vao giua 2 chu so cua so do roi lay so moi tru di 6 lan chu so hang tram ta duoc so bang 8 lan so da cho
Tim 1 so co 2 chu so, biet rang khi viet them so 0 vao giua 2 chu so do ta duoc 1 so lon gap 7 lan so da cho
tim 2 so co 2 chu so biet rang khi them chu so 0 vao giua hai chu so cua so do thi duoc so moi gap 7 lan so da cho
neu ta viet them chu so 0 vao giua cac chu so cua mot so co 2 chu so ta duoc mot so moi co 3 chu so lon hon so dau tien 7 lan. tim so do