So chan la so tu nhien co chu so tan cung la 0;2;4;6;8 ; so le la so tu nhien co chu so tan cung la 1;3;5;7;9;.Hai so chan ( hoac so le ) thi
hon kem nhau 2 don vi a)viet tap C cac chang nho hon 10.b) viet tap hop L cac so le lon hon 10 nhung nho hon 20.c)viet tap hop A ba chu so chan lien tiep trong do so nho nhat la 18.d)viet tap hop B bon so le lien tiep, trong do so lon nhat la 31
Goi M la tap hop cac so tu nhien co 2 chu so ma chu so hang chuc be hon
chu so hang don vi la S .Phan tu lon nhat cua F.
cho G la tap hop cac stn co 2 chu so ma chu so hang chuc lon hon chu so hang don vi la 6 so phan tu cua tap hop nay la
Q la tap hop so tu nhien co 2 chu so ma trong moi so chu so hang chuc lon hon chu so hang don vi la 2 . tinh so phan tu cua tap hop Q
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
tìm một số tự nhiên có 3 chữ số biet sau khi bo di chu so hang don vi so lon nhat co the tim la ta duoc so moi kem so ban dau 180 don vi so lon nhat co the tim
tim so lon nhat co 5 chu so , ma moi chu so cach nhau 2 don vi !
tong cua 3 so la so lon nhat co 3 chu so. Neu lay so thu nhat chia cho so thu 2 thi duoc thuong la 5 du 3. So thu nhat hon tong cua 2 so kia la 7 don vi. So thu nhat hon so thu hai la .......
co bao nhieu so co 2 chu so ma chu so hang chuc lon hon chu so hang don vi