A microprocessor production plant produces chips of three categories: Grade A, Grade B, and Grade C. Every single chip goes through rigorous testing before being sent out to the stores. For every 50 Grade A chips that are tested, 32 pass, 12 fail, and the remaining chips are sent to be re-tested. For every 75 Grade B chips, 45 pass, 24 fail, and the rest are re-tested. And for every 60 Grade C chips, 23 pass, 17 fail, and the rest are re-tested. The plant distributes its production of Grade A, B, and C chips as 55%, 30%, and 15% respectively. A randomly selected chip was independently tested by five QA engineers, and it was sent for re-testing by three of the QA engineers. What is the probability that the chip was a Grade B chip?