1. You are travelling down a road to a village. You reach a fork in the road and find a pair of identical twin brothers standing there. One of the brothers always tells the truth and the other always lies. If you are allowed to ask only one question to one of the brothers to find which is the correct road to the village, what is your question ?
Answer: If the brother you are speaking to is the one who always lies, then he will say "no" as he knows that his brother who speaks the truth would anwser "yes". If the brother you are speaking to is the one who speaks the truth, he will say "no" as he knows that his brother will lie about it being the correct road. Either way an answer "no" tells you it is actually the right road. Similarly if you are pointing to the wrong road you will get the answer "yes".
2. A boat has a ladder that has six rungs, each rung is 30cm apart. The bottom rung is 30cm from the water. The tide rises at 20cm every 15 minutes. High tide peaks in one hour.
When the tide is at its highest, how many rungs are under water?
Answer: None, the boat rises with the tide.