If # is an operation which results in adding the digits of…

If # is an operation which results in adding the digits of integer until a single digit is left, what is the probability K that a number picked up in first 90 positive integers will have the result of # as an odd digit ?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #34238