tim mot so tu nhien co ba chu so biet rang neu tang chu so hang tram len n don vi va giam chu so hang chuc di n don vi thi ta duoc so co chu so gap n lan chu so da cho

bai 13 :tim tich cua so nho nhat co ba chu so khac nhau voi so chan lon nhat co mot chu so.

bai 14 :tim mot so,biet rang neu giam so do di 5 lan sau do them 10 don vi thi duoc so le nho nhat co hai chu so.

bai 15 :tim mot so biet rang neu gap so do len 4 lan,duoc bao nhieu lai gap len 6 lan thi duoc 360

bai 12:Mot vuon co so cay buoi bang 1phan2 cay cam,biet so cay cam bang so chan lon nhat co 3 chu so.Hoivuon do co tat ca bao nhieu cay buoi va cam?

bai 13:tim tich cua so nho nhatco ba chu so khac nhau voi so chan lon nhat co mot chu so.

bai 14:tim mot so,biet rang giam so do di 5 lan sau do them 10 don vi thi duoc so le nho nhat co hai chu so.

bai 15:tim mot so biet rang neu gap so do len 4 lan,duoc bao nhieu lai gap len 6 lan thi duoc 360.

1. tim so tu nhien co 3 chu so,biet so do gap 20 lan tong cac chu so cua no

2. tim so tu nhien co 2 chu so, biet rang neu lay so do chia cho hieu cua chu so hang chuc va hang don vi, thi ta duoc thuong la 28 du 1

3. tim 1 so tu nhien co ba chu so , biet rang neu chuyen chu so cuoi len truoc chu so dau ta duoc so moi hon so da cho 765 don vi

tim 2 so tu nhien co hieu la 45 biet rang neu them vao so lon 15 don vi va giam so be di 8 don vi thi duoc 2 so moi co thuong bang 5

tim so tu nhien co hai chu so biet rang neu viet chu so 0 xen giua so hang chuc va hang don vi cua so do ta duoc so moi gap 10 lan so phai tim neu viet chu so 1 vao ben traiso vua nhan thi so do gap len 3 lan

tim so tu nhien co 2 chu so ,biet rang neu viet them 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.

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

1) cho 5 chu so khac nhau voi cung ca 5 chu so nay co the lap duoc bao nhieu so co 5 chu so 

2) viet cac so tu nhien co 4 chu so trong do co hai chu so 3, mot chu so 2va mot chu so 1

3)tim so tu nhien co tan  cung bang 3 biet rang neu xoa chu so hang don vi thi so do giam di 1992 don vi