I got this brain teaser from Khan Academy Online. Me and my two boys really enjoy looking at their brain teasers. The link is below if you want to see it for yourself. But here it is:
You have a group of 5 people. Four of them are Togglers. One of them is a Truthteller. Your quest is to find the truth teller.
Let me explain what a toggler is. A toggler is a person that "toggles" between the truth and a lie. If you ask them a question they will either tell you the truth or a lie. But it always toggles back and forth.
The truth teller always tells the truth.
Find the Truth teller by asking two questions.
You are allowed to ask two questions to one person each. That means you can ask anyone any question, and for the second question, you can ask that same person or another individual.
Now what questions would you ask to find the truth teller?