Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

A thief enters a store and threatens the clerk, forcing her to open the safe. The clerk says, “The code for the safe is different every day, and if you hurt me you’ll never get the code.” But the thief manages to guess the code on his own. How did he do it?

Take number 1000 and then add 20 to it.
Now add 1000 one more time.
Now add 30.
Now add 1000 one more time.
Now add 40.
Now add 1000 one more time.
Now add 10.

What is the total?

You have a square. What you have to do is cut and reassemble the square such that you create a Red Cross sign that has the same volume as that of the square.

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

Eight of us go fourth, not back, to protect our king from an attack. What are we?

Which letter of the alphabet has the most water?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?