What is the next shape from answers A, B, C, and D figure?

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

What has many keys but can’t open a single lock?

I have an eye but still cannot see.

Who am I?

In a university, a professor gave a set of three problems to the three brilliant students of his class. See the image for the questions.

Move three sticks of the spiral below to form a square.

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

Can you find out who is the kidnapper in below Picture and why, Explain ?

There was a strange boy who was born before his father. How can this be possible?

One night, a man runs away from home. He turns left and keeps running. After some time he turns left again and keeps running. Later, he turns left one more time and runs back home—but when he gets home, he finds a man in a mask. Who was the man in the mask?