I’m tall when I’m young, and I’m short when I’m old. What am I?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

What Deficiency does the below rebus represent?

VIT_MIN

Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()

A container contains 100 eggs. They can be either fresh or rotten. What is sure is the fact that there is at least one fresh egg in that container.

If you are asked to pick two eggs randomly from the container, at least one of them will be rotten.

Can you calculate how many eggs in that container are fresh?

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

Replace the question mark with the correct number below.

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

What occurs twice in a week, once in a year but never in a day?