A die is thrown at most 77 times until we get an odd number.
If the die is thrown in total an even number of times, what is the probability that the last throw is odd?
According to Gregmat the right answer is (21/64). However, I think the wording is misleading/incorrect. We stop throwing the die once we get an odd number, correct? So conditional on ending throwing after 2,4,6 times, the prob. that the die landed odd the last time is 1. Otherwise we would not have stopped throwing before reaching 7 throws.