If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.

If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.

Will you accept that bet?

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

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

Why do you find that most of the buildings are deprived of the 13th floor?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

In the picture that is attached with this question, you can find a square which comprises of four little squares inside it. Consider this square to be made with matchsticks. You have to remove two matchsticks such that only two squares remain instead of five.How will you do it ?

If in a code language, DISTANCE is written as IDTUBECN and DOCUMENT is written as ODDVNTNE, the how will THURSDAY be coded as in the same language?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?