It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?

Find the last number in the series below:

voN luJ yaM raM ---

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

In the image given, you can find several triangles. Can you count them all?

What is the word or phrase?

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

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