You have to do a survey in the Truth city as everyone living there speaks the truth.
The Lie city where everyone lies is right next to it and there is no way that you can find out which is which (No sign boards, etc.)
You come across two paths one leads to Truth city and the other leads to Lie city.
A person comes from behind you.
You don’t know whether he is from Truth city or Lie city.
What can you ask him to choose the right path to Truth city?