What always comes into a house through the keyhole?

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

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?

Replace the (?) with the correct mathematical signs to make the expression equal to 59.

18 ? 12 ? 4 ? 5 = 59

What part of the chicken has the most feathers?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

What is the unique property of the following words ?
* Revive
* Banana
* Grammar
* Voodoo
* Assess
* Potato
* Dresser
* Uneven

I inserted a coin in a bottle and closed its mouth with the help of a cork. Now, I was able to take the coin out from the bottle without taking out the cork or breaking the bottle. Can you tell me how I did it?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

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