In which direction should the missing arrow point?

Solve the following series:
AZ, GT, MN, __, YB

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

How old is your son? asked a man to his neighbour. My son is five times as old as my daughter and my wife is five times as old as my son. I am twice as old as my wife whereas my grandmother, who is celebrating her eighty-first birthday is as old as all of us put together.

How old is the man's son ?

A large water tank has two inlet pipes (a large one and a small one) and one outlet pipe. It takes 3 hours to fill the tank with the large inlet pipe. On the other hand, it takes 6 hours to fill the tank with the small inlet pipe. The outlet pipe allows the full tank to be emptied in 9 hours.

What fraction of the tank (initially empty) will be filled in 0.64 hours if all three pipes are in operation? Give your answer to two decimal places (e.g., 0.25, 0.5, or 0.75).

What is the longest word in the dictionary?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

What will you call your mother's brother's brother-in-law?