Tim mot so tu nhien co 2 chu so,biet rang neu viet cac chu so cua so ay theo thu tu nguoc lai thi duoc so moi gap so ban dau 3 lan va 13 don vi
Bai 1 :
a) Tim abcd biet : a x bcd = 1001 b) Tim ab ; biet ab x aba = abab
Bai 2 Tim so co hai chu so, biet rang neu viet them chu so 6 vao ben trai so da cho thi duoc so moi gap 7 lan so cu.
Bai 3: Tim so co ba chu so, biet rang neu viet them chu so 3 vao ben trai so da cho thi duoc so moi gap 7 lan so do
Bai 4 :
a) Tim cac so a7b cung chia het cho 5 va 9 b) Tim cac aso 1ab cung chia het cho 5 va 3
Bai 5 : Tim so co hai chu so, biet rang so do chia cho hang don vi cua no thi duoc thuong la 6, du 5.
Bai 6: Cho so co hai chu so trong do chu so hang don vi la 7. Tim so da cho, biet rang neu chia so do cho tong cac chu so cua no thi duoc thuong la 5 va du 12.
tim mot so tu nhien co 3 chu so biet rang neu chuyen chu so 7 tan cung cua so do len dau thi duoc mot so moi gap 2 lan so cu va them 21 don vi
cho 1 so co 2 chu so neu doi cac chu so cua so do ta duoc so moi gap 4, 5 lan so da cho . tim so do
tim mot so tu nhien co hai chu so, biet rang neu viet cac chu so cua so ay theo thu tu nguoc lai thi duoc so moi, lay so moi chia cho so ban dau thi duoc thuong la 3 du 13
tim so tu nhien co 2 chu so biet rang neu viet chu so 0 xen giua chu so hang chuc va hang don vi cua so do ta duoc so moi gap 10 lan so can tim . Neu viet them chu so 1 vao ben trai so vua nhan duoc thi so do gap len 3 lan . So can tim la
Mot so co hai chu so bang 3 lan tong cac chu so cua no cong voi 7.Neu viet so do theo thu tu nguoc lai thi duoc so moi bang 7 lan tong cac chu so cua no cong voi 3.Tim so da cho
tim mot so co 6 chu so biet rang neu viet them chu so 0 vao giua hang nghin va hang tram thi duoc so moi gap 9 lan so can tim
Giai bai toan nay ho minh voi tim 1 so co 4 chu so biet rang neu viet cac chu so cua no theo thu tu nguoc lai thi ta duoc mot so bang 4 lan so da cho?