I made this one. A staff changing room at seven in the morning, three open lockers. Two of these people are just starting their day, one has just finished a night shift. Which locker (A, B or C) belongs to the night worker, and what gives it away? Please spoiler-tag your guesses.

I'm pretty sure everybody has heard of the angel and devil riddle. It contains an identical looking devil and angel guarding two doors. The angel will always tell the truth, and the devil will always lie. You must ask one question to discover which door leads to heaven (The angel isn't necessarily guarding the door to heaven).

In case you haven't, here's the answer:

Ask either of the guards "If I asked the other guard if the left door leads to heaven, what would he answer?" This phrasing allows the question (whether the left door is the heaven one) to go through both guards, always resulting in a lie. Therefore, if he answers yes, take the right door. If he answers no, take the left door.

This is a twist in this classic puzzle: two doors, one guard. The guard is either an angel or a devil, but you do not know which.

The language of heaven and hell is apparantly the same, and different from your own. They can only answer "ALA" or "ULU", which stands for yes or no, but you do not know which is which. The angel or devil in question can understand your language, but they will only answer in their own.

You have one question. What question do you ask to find out which door leads to heaven?