Three went in, two came out
The puzzle
Three people went into a restaurant and two came out.
Nobody was left inside, and there is no back door.
See the answer (spoiler)
Spoilers from here on. If you want to work it out yourself, leave this folded and move on.
Answer
One of the three works there.
They ate together, and then she started her shift.
Two of them left as customers; the third is behind the counter.
