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

If eleven plus two equals one, what does nine plus five equal?

What is the longest word in the dictionary?

I am sure no one can have two things for dinner. what are they?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

I start and end with 500 and carry a 5 in my heart. But I require the first letter and the first number to be complete. I am the name of a King.

Who am I ?

There's a day, that comes around once a year.
To celebrate the man, you hold dear.
He gave you life, love and will pick you up if you fall.
When it comes to guys like him, He's the best of all.
Who is he?

Rectify the following equality 101 - 102 = 1 by moving just one digit.