Originally Posted by raymor

Assuming each answer is equally likely, that would mean the combined odds are:
50% * 50% + 25% * 50% = 37.5%

Since 37.5% isn't a listed answer, the odds of selecting the correct answer are 0%, given the assumption that those four (three) answers are equally likely.

However, if you define a) and d) as different answers, the odds are 25% and either a or d is correct, but not both.

The odds that we've been geek-trolled? 100%.