questions - Yes/no answer to "Have you closed all of your tickets?" if there were no tickets to begin with

My boss asked the question, "Have you closed all of your tickets?" to me and my co-workers. One of my co-workers, who did not have any tickets to begin with, answered yes. We are conflicted as to weather yes is the correct answer to this question, vs. "Are all of your tickets closed?" or, "Do you have any open tickets?"

Answer

Not all questions can have a yes or no answer, and the way the question is phrased (and the presupposiitons it makes) often determines if an answer applies, and what it is.

The classic example of this is "have you stopped beating your wife"?

The REAL correct answer to the question is not yes or no, but to clear up the presupposition that there were open tickets to begin with.

However if you want to be pedantic you can logically get to either "yes" OR "no":

Every ticket assigned to me (0 of them) is now closed, so yes.

or

I have closed NO tickets today, so no.