What was your question?

You leave your job interview in Liar and Truthteller Town with two other candidates who seem to know each other.
The interviewer has told you that one of them is a Liar and one is a Truthteller; but you were so nervous you didn’t ask him which was which. Out on the sidewalk the three of you find the local Witch selling apples from a booth. Wicked witches are notorious for making apples that will put you to sleep for one hundred years and you have a train to catch. But those apples look delicious. So you turn to the other candidates and randomly ask one for advice. Her answer tells you all you need to know about the local witch’s apples. What was your question?

Click here for the solution

Your question was: “Would the other person tell me that this apple is all right to eat?”

If the person is the Truthteller and the apple is fine, she will say, No, because that’s what the Liar would say. If the person
is the Liar and the apple is fine, she will say, No, because that’s not what the Truthteller would say.
Similarly, if the apple will put you to sleep, the person will have to say, Yes.

more riddles

How many descendants?

Very few people bother to determine what an amazing potential for overpopulation they have. Let us consider yours. If you and your wife have a meager two children, it would seem you are not adding much to the world. But let's suppose that in 5 years each of your...

read more

How many – how much?

The engineering department was arranging for a rather expensive catered lunch to bid farewell to their retiring colleague. They calculated that it would cost each person $30. One good mathematician remarked, "It's lucky that there aren't five fewer of us to split the...

read more

Where’s the other dollar?

Three guys walk into town. They go into a hotel and ask for a room they can share. The clerk has just the thing they want for thirty dollars. The clerk sends them to the room, takes out the ledger, and realizes that he made a mistake. The room costs only twenty-five...

read more


The letters on the glass doors of a beauty parlor read correctly when viewed from the street. How would this lettering appear when seen in a mirror in the parlor, which reflects it from a mirror, which reflects it from another mirror?The lettering would appear...

read more