What is black when you buy it, red when you use it, and gray when you throw it away?

Can you decipher the below rebus?

PBLUESAISNUERSES

Why did Navjot Singh Sidhu put the new January calendar in the freezer

The cream is heavier than Milk. True or False?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

Here is what you have to do. You have to throw a ball as hard as you can but it must return back to you even if it does not bounce at anything. Also, you have nothing attached to the ball. There is no one on the other end to catch that ball and throw it back at you.

How will you do it?

A sea diver is a real show-off. He showed everyone that he can hold his breath underwater for 15 minutes.

I went to the diver and told him that I can be underwater for double the time i.e 30 minutes.
He responded that he will give me 100$ if I would be able to do it. I won 100$.

What did I do?

Through your logical capabilities, can you make 7 an even?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

You stand in front of two doors. A guard stands next to each door. You know the following things: one path leads to paradise, the other leads to death. You cannot distinguish between the two doors. You also know that one of the two guards always tells the truth and the other always lies. You have permission to ask one guard one question to discover which door leads to paradise. What one question would you ask to guarantee you enter the door to paradise?