Cac chu so phan muoi, phan tram, phan nghin cua mot so thap phan co 3 chu so o phan thap phan la 3 so le lien tiep . Tong cac chu so o phan thap phan bang phan nguyen cua so do, cac chu so o phan nguyen va phan thap phan deu khac nhau . Tim so thap phan do ?