Question : This is a classic brain teaser and probably appears in a variety of forms.
The version here is based on the 1970’s series of Dr Who, “The Pyramids of Mars”.
You are forced to flee for your life down a long tunnel.
At the end of the tunnel are two doors and next to each door stands a robot. You must make a decision as to which door to go through.
However, one door leads to certain death and the other to freedom but you do not know which is which!
Fortunately you are allowed to ask one and only one question to either of the two robots.
Unfortunately one robot can only lie and the other can only tell the truth.
As with the doors you do not know which robot is which.
What is your question and which door do you take ?
Answer : Turn to either of the two robots and ask the following question:
“If I ask your companion to point to the door that leads to freedom which will he point to ?”
Whichever door the robot suggests make sure you take the other!