tim so tu nhien co 2 chu so biet rang neu viet chinh so do xen vao giua hai chu so cua no thi so do tang len 99 lan
mot so tu nhien co 5 chu so. biet rang viet them 1 vao ben phai va them chu so1 vao ben trai thi ta duoc so moi lon gap 3 lan so ban dau. tim so ban dau
mot so tu nhien co hai chu so. Chu so hang don vi gap 2 lan chu so hang chuc. Neu them chu so 1 vao giua chu so ay thi duoc 1 so moi lon hon so ban dau la 370. Tim số ban đầu.
tim hai so tu nhien co hai chu so biet tong hai chu so do bang 10 va neu viet theo thu tu nguoc lai thu duoc so moi kem so phai tim 54 don vi
tim phan so co dong thoi cac tinh chat sau
a/Tu cua phan so la so tu nhien co mot chu so
b/Hieu giua tu so va mau so la 4
c/Neu giu nguyen tu so va viet them vao ben phai mau so mot chu so dung bang tu so,thi duoc phan so moi bang phan so 1/5
tim so co 4 chu so biet rang chu so hang tram, hang nghin, chuc, don vi theo thu tu do lam thanh 4 so tu nhien lien tiep tang dan
tim so tu nhien N co 2 chu so,biet rang 2N+1 va 3N+1 la cac so chinh phuong
mot so tu nhien co 2 chu so voi tong cac chu so bang 14. neu viet nguoc lai thi duoc 1 so tu nhien co 2 chu so ,lon hon so ban dau 18 don vi . tim so tu nhien ban dau
mot so tu nhien co 2 chu so voi tong cac chu so bang 14. neu viet nguoc lai thi duoc 1 so tu nhien co 2 chu so ,lon hon so ban dau 18 don vi . tim so tu nhien ban dau
giai cu the