The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

I have a big mouth and I am also quite loud! I am NOT a gossip but I do get involved with everyone's dirty business.

That attorney is my brother, testified the accountant.

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

Who is lying?

Why is the Hole below a Lock?

Prove that the below maths equation is true.

8 + 8 = 91

John is 45 years older than his son Jacob. If you find similarities between their ages, both of their ages contain prime numbers as the digits. Also, John's age is the reverse of Jacob's age.

Can you find their ages?

You have a basket containing ten apples. You have ten friends, who each desire an apple. You give each of your friends one apple.
Now all your friends have one apple each, yet there is an apple remaining in the basket.
How?

There is one four-digit whole number n, such that the last four digits of n2 are the original number n

What can go up a chimney down, but can’t go down a chimney up?

Find the smallest sentence with all the English alphabet.