What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

What is the next number in this series?

4,12,84,3612....

Which is the correct shadow of the bird?

A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?

You know three triplets: Frank John and Wayne (need to return your money). Frank always tells the truth while John and Wayne always lie. You meet one of them on the road and can ask him a three-word question.
Which question, will you ask?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

Can you find a five letter word that is left with only two letters if one is removed?

What number divided by 4 is the same as that number minus 4?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?