Why is Saturday stronger than Monday?

John and his wife were living in a rural place. On a particular day, John's wife fell ill and he called the local doctor. When the doctor picked up, he said, "Doctor, my wife is ill. She might have appendicitis."

"This can't be possible! I took out her appendix two years ago myself," the doctor explained.

When diagnosed, John's wife was found to have appendicitis. How can this be possible?

There are six people in a family namely M, N, O, P, Q and R.

R and O are brother and sister.

N is the brother of Q's husband.
P is the father of M and grandfather of R.

How many male members are in the family?

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

When is the top of a mountain similar to a savings account?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Before reading ahead, you must know the fact that only one of the people here is telling the truth.

A says that B is lying.
B says that C is lying.
C says both A and B are lying.

Can you find out who is speaking the truth?

Can you start the fire using two pieces of wood?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

How can you make number one disappear by adding something to it?