Only one color, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

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

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?

why number 8549176320 is one of a kind?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

There are three boxes on a table. One of the box contains Gold and the other two are empty. A printed message contains in each box. One of the message is true and the other two are lies.

The first box says "The Gold is not here".

The Second box says "The Gold is not here".

The Third box says "The Gold is in the Second box".

Which box has the Gold?

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den

A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?