Gọi số đó là abc
Theo bài ra ta có cba-abc=792
(100c+10b+a)-(100a+10b+c)=792
100c+10b+a-100a-10b-c=792
99c-99a=792
99(c-a)=792
c-a=8
mà c:a=3
3a-a=8
2a=8
a=4; c=12(vô lý)
Không có abc
Tim mot do tu nhien co 3 chu so abc biet rang neu doi chu so hang tram va chu so hang don vi cho nhau thi so moi lon hon so cu 792 đơn vị ,chu so hang don vi gap 3 lan chu so hang chuc
tim so co 3 chu so biet rang chu so hang tram gap doi chu so hang chuc va chu so hang chuc nhieu hon chu so hang don vi la 4
tim so co 3 chu so biet chu so hang tram nho hon chu so hang chuc neu doi 2 chu so nay cho nhau ta duoc so moi hon so cu 720don vi biet tong cua chu so hang don vi la 7
tim tat cac so tu nhien co ba chu so thoan man cac tinh chat sau : co tong cac chu so bang 9 chu so hang chuc lom hon chu so hang don vi la 2 don vi va neu ta doi chu so hang tram cho hang don vi thi duoc so moi lon hon so ban dau la 198 don vi
mot so chan co 4 chu so biet rang hang tram va chu so hang chuc lap thanh mot so gap 3 lan chu so hang nghin va gsp 2 lan chu so hang don vi
mot so co hai chu so trong do chu so hang chuc gap 3 lan chu so hang don vi neu doi chu so do thi duoc mot so nho hon da cho 36 don vi tim do
viet tap hop cac so tu nhien co hai chu so,trong do:
a,chu so hang don vi lon hon chu so hang chuc 4 don vi
b,chu so hang don vi gap 3 lan chu so hang chuc
c,chu so hang don vi nho hon chu so hang chuc va tong hai chu so =17
cho 1 so co 3 chu so ma chu so hang don vi lon hon hang tram . neu viet chu so hang don vi len truoc hang tram thi duoc 1 so moi lon hon so da cho la 765 , tim so da cho
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
