Q. A traveler meets a native in the jungle at a the fork in the trail, where only one path goes to the village. The traveler does not know which path to take and knows that the native could be either from the tribe of Truth-tellers, who always tell the truth, or from the Liars, who always lie. What is one question he could ask the native to discover the path to the village?

Ans. There are at least a hundred variations on this problem and they are not all based on the same idea. This is one of the simplest but it is still tricky. The idea is to find a question such that either native will answer the same. That requires that the question include some sort of double negative, which will cancel out the fact that he may be lying. One example is "If you were from the other tribe, which path would you say goes to the village?" The truth teller will point to the wrong path, and so will the liar (think about it). So whatever path is pointed to, take the other one.

Q. Two fathers and two sons went fishing. Each caught exactly one fish and yet there were only three fish caught. Why?

Ans. This is a classic in creative thinking. Many problems are set up to get you to expect one thing and then shock you be having the obvious be false. At first we think that two fathers and two sons means four people. But each caught a fish and yet only three fish were caught. Hence, there were only three people. How could that be? It must be that one of the three people fulfills a dual role of being both a father and a son. Is that possible? Of course. So it must have been a grandfather, a father and his son who went fishing.

Q. A drawer contains 10 black and 10 brown socks that are all mixed up. What is the fewest number of socks you can take from the drawer without looking and be sure to get a pair of the same color?

Ans. In this problem, it is very important to notice that the color required is not specified. It is only necessary to pick three socks to be guaranteed of getting at least two black or two brown socks.

Q. A farmer has a fox, goose and a bag of grain, and one boat to cross a stream, which is only big enough to take one of the three across with him at a time. If left alone together, the fox would eat the goose and the goose would eat the grain. How can the farmer get all three across the stream?

Ans. Before I try to solve any problem I usually draw a picture and even though I don't here, I did when I solved it (highly recommended). The first trip requires the farmer to take the goose across, because it cannot be left with either grain or the fox. On the next trip, the farmer may take either fox or grain, but then he must bring back the goose. On the third trip, the farmer takes the remaining item, but leaves the goose on the first shore. He then makes a fourth trip to bring the goose. Thus, four trips are required, and the goose ends up crossing three times.

A teacher asked a student to write 55.
Student asked: How?
Teacher: Write 5 and beside it another 5!
The student wrote 5 and stopped.
teacher: What are you waiting for?
student: I don't know which side to write the other 5!

A: Why are you crying?
B: The elephant is dead.
A: Was he your pet?
B: No, but I'm the one who must dig his grave

My friend said he knew a man with a wooden leg named Smith.
So I asked him "What was the name of his other leg?"

A family of mice were surprised by a big cat. Father Mouse jumped and and said, "Bow-wow!" The cat ran away. "What was that, Father?" asked Baby Mouse. "Well, son, that's why it's important to learn a second language."

Girl: You would be a good dancer except for two things.
Boy: What are the two things?
Girl: Your feet.

A: I have the perfect son.
B: Does he smoke?
A: No, he doesn't.
B: Does he drink whiskey?
A: No, he doesn't.
B: Does he ever come home late?
A: No, he doesn't.
B: I guess you really do have the perfect son. How old is he?
A: He will be six months old next Wednesday.