No one wants to have it, but if one got it, he does not want to lose it. What is It?

In a classic wine shop, the list of three most popular wines are:
- The cost of 1 French wine bottle: 500$
- The cost of 1 German wine bottle: 100$
- The cost of 20 Dutch wine bottles: 100$

John entered the wine shop and he needs to buy
- All three types of wine bottles.
- Needs to buy Dutch wine bottles in multiples of 20.
- Need to buy 100 wine bottles in total.

John has only 10000$. How many wine bottles of each type, John must buy?

You can see it everyday, But cannot touch it at will. What is it?

Count the number of balls in picture below:

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

The ages of a father and son add up to 66.
The father's age is the son's age reversed.
How old could they be?
(3 possible solutions).

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

What runs around the whole yard without moving?

What Adam and Eve do not have but the rest of the people have?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?