Riddle: You go down a long path until it "splits" into two. You don't know which one is the right, but there are three men. One always says the truth, one always lies and one sometimes lies, sometimes says the truth. You don't know who is who. You can only ask two questions to any of them. How do you surely find out, which is the right path?
Answer: 1: Man who always says the truth.
2: Man who always lies.
3: Man who sometimes lies, sometimes says the truth.
First, ask anyone "Which one of the others says the truth more often?". If you ask 1, he'll point to 3. If you ask 2, he'll also point to 3. If you ask 3, he'll point to 1 or 2. Talk to the man, who didn't point or "got pointed". It won't be 3. Ask "What would say the man, which is the exact opposite of you, which path is the right one?". Both will point to the wrong path.