People put me on the table and cut me but do not eat me. What am I?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

Prove that the below maths equation is true.

8 + 8 = 91

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

If 21x = 79x, what is the value of x?

That attorney is my brother, testified the accountant.

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

Who is lying?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

Name the three-letter word that can complete the below words:

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

Seven Robbers robbed a bank and hide the coins in a lonely place.
They decide to divide the money equally the next morning. Two greedy robbers decided to cheat the others and reach the place at night. They equally divided the coins between them, one coin left. So they called another robber and then they decided to divide equally among the three. Sadly again one coin left. The same thing happened to the 4th 5th and the 6th robber.
However, when the 7th robber reached in the morning, they can divide the coins equally.

How many coins were there in total?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?