Detailed Instructions: The task is to generate the correct answer for a given math problem.
Q: Problem: if # is an operation which results in adding the digits of integer until a single digit is left , what is the probability that a number picked up in first 90 positive integers will have the result of # as an odd digit ? ( example 99 = 9 + 9 = 18 = 1 + 8 = 9 , so # = 9 )
A:
5 /