There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

What runs around the whole yard without moving?

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

Two old friends, Jack and Bill, meet after a long time.

Three kids
Jack: Hey, how are you, man?
Bill: Not bad, got married and I have three kids now.
Jack: That's awesome. How old are they?
Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.
Jack: Cool..But I still don't know.
Bill: My eldest kid just started taking piano lessons.
Jack: Oh, now I get it.

How old are Bill's kids?

Highly detail-oriented individuals excel at this type of optical illusion challenge. It requires not just good eyesight but also the ability to distinguish subtle differences quickly. Finding the 6 among all these 9's could indicate a high level of IQ and superior observational skills.

A few friends are enjoying their sea voyage in a boat full of apples. On the way, they felt hungry and thus decided to eat the apples. Together, they ate two dozen of apples. When they have eaten the apples, will there be any change in the water level?