So sánh 291 và 535
291=213.7=(213)7=81927
535=55.7=(55)7=31257
Vì 81927 > 31257
Nên 291 > 535
So sánh 10750 và 7375
10750=1072.25=(1072)25=1144925
7375=733.25=(733)25=38901725
Vì 1144925 < 38901725
Nên 10750 < 7375
1.Cho so N la so co hai chu so chia het cho 3.Neu viet xen so 0 vao giua hai chu so do roi cong no voi hai lan chu so hang chuc cua so N ta duoc so moi gap 9 lan so N.Tim so do
2.Tong hai so thap phan la 60,1.Neu dich dau phay cua so nho sang ben phai mot hang roi dem tru di so lon thi ta duoc 219,52.Tim hai so do.
3.Tim so co hai chu so biet neu ta them so 33 vao giua hai chu so do thi duoc mot so moi gap so phai tim 89 lan.
Tim 2 so, biet so lon gap 9 lan so be va so lon la so co ba chu so voi chu so hang tram la 4, dong thoi neu xoa di chu so hang tram cua so lon thi duoc so be
Tim so co 4 chu so biet so do cong voi so co 2 chu so tao boi chu so hang nghìn ,tram va so co 2 chu so tao boi chu so hang chuc ,don vi cua so do tong la 7968
Tim so tu nhien co hai chu so khac nhau . Biet rang: hai chu so cua so do deu la so nguyen to . Tich cua so do voi cac chu so cua no la so co 3 chu so giong nhau duoc tao thanh tu chu so hang don vi cua so do.
tim so co hai chu so biet rang neu ta viet them chu so 1 vao giua hai chu so cua so do ta duoc so moi gap so 9 lan so phai tim.tim so phai tim
so 2^2 va 5^2 viet lien nhau dc so 425 co 3 chu so
so 2^3 va 5^3 viet lien nhau dc so 8125 co 4 chu so
so 2^4 va 5^4 viet lien nhau d so 16625 co 5 chu so
chung minh rang so 2^2007 va so 5^2007 viet lien nhau dc so co 2008 chu so
Cho 2 so lon hon 320 co tong=836 chu so hang tram cua so thu1 la 5 chu so hang tram cua so thu 2 la 3 neu gach bo chu so 5 va 3 thi se duoc 2 so co 2 chu so ma so nay gap 2 lan so kia tim hieu hai so do
Người ta viêt thêm chư so 0 vào giữa 2 chu so cua so co 2 chu so sau do lập ti so giữa so co 3 chu so trên va so da cho hỏi gia tri so nguyên lon nhật va nho nhật cua ti so nay la bao nhiêu
So N la so co 2 chu so chia het cho 3.Neu xem chu so 0 vao giua hai so roi cong voi 2 lan chu so hang chuc cua so N ta duoc so moi gap 9 lan so N
dien dung sai
a/tich cua hai so nguyen duong la mot so nguyen duong
b/tich cua hai so nguyen am la mot so nguyen am
c/tich cua 2 so nguyen cung dau luon lon hon moi so do
d/tich cua hai so nguyen khac dau luon nho hon moi so do
e/neu tich hai so nguyen la mot so nguyen duong thi hai so do deu la so nguyen duong
f/neu tich hai so nguyen la mot so nguyen am thi hai so do deu la so nguyen am
