In a 1/N fraction, if we cannot write the denominator in terms of factors of 2's and/or 5's, then the decimal repeats......and the maximum length of its repeating string of digits is never greater than N - 1 digits

In a 1/N fraction, if we cannot write the denominator in terms of factors of 2's and/or 5's, then the decimal repeats......and the maximum length of its repeating string of digits is never greater than N - 1 digits