Was solving the GO 2019 pdf when I encountered this question asked in TIFR 2017. Although I have understood this question, I have one doubt-
It is mentioned in the question that for a 3-bit number, the ordering (000, 100, 101, 111, 110, 010, 011, 001) is one of the possible Gray codes.
Then, how many such orders are there for an n-bit number?