tim tat ca cac so tu nhien có 2 chu so biet rang chu so hang don vi nho hon chu so hang chuc la 2 va tich cua chu so do cua no luon lon hon tong cua hai chu so cua nó la 34 don vi

tim so co 3 chu so. Biet trung binh cong cua 3 chu so la 2 va chu so hang tram bang tong chu so hang chuc va hang don vi. Tim 3 chu so do ?

Tong cac chu so cua so tu nhien co 3 chu so la 12. Chu so hang chuc bang tong chu so hang tram va hang don vi. Neu doi vi tri chu so hang tram va hang don vi thi duoc so moi hon so cu la 396. Tim so ban dau.

                       (giải ra)

Tim so co hai chu so, biet chu so hang don vi hon chu so hang chuc la 3, tong cua so phai tim va so viet theo thu tu nguoc lai cua so do bang 143

tim so co hai chu so biet tong cua hai chu so do la so lon hon 10.ti so cua chu so hang chuc va chu so hang don vi la 2/3

tim so co chu so biet trung binh cong cua 3 chu so bang 2 va chu so hang tram bang tong cac chu so hang chuc va hang don vi 

Tim mot so co ba chu so biet trung binh cong cua ba so do bang 2va chu so hang tram bang tong cac chu so hang chuc va hang don vi

tong cac chu so cua 1 so co 3 chu so la 21 chu so hang don vi lon hon chu so hang chuc .neu ta doi vi tri chu so hang don vi va chu so hang tram thi duoc mot so moi co gia tri lon hon so cu la 198. tim so cu .

giup mk nhe

tim mot so biet so do nho hon 800 va chu so hang tram nho hon chu so hang chuc , chu so hang chuc nho hon chu so hang don vi va tong cac so cua chu so cua so do bang 24