What is black when you buy it, red when you use it, and gray when you throw it away?

What brings you down but never up?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

The horse jumps over the king.
Strangely there is absolutely no scratch on him.

Can anyone explain, how is this possible?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

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?

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???

What is the next shape from answers A, B, C, and D figure?