I travel all around the world but always stay in the corner. What am I?

What Deficiency does the below rebus represent?

VIT_MIN

The more you take me, the more you leave me behind.
Who Am I?

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

In the image given, you can find several triangles. Can you count them all?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

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?

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

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?