Manish has to secure 40% marks to pass his B.tech final exams.
He got just 40 marks and failed by 40-marks.

What is the maximum marks?

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

What have one eye but still cannot see?

As shown in the image, the nine Dogs are square fenced. By constructing just two square fences can you make sure that two Dogs cannot meet each other without crossing the fence?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

John was so frustrated to be the suspect of being a sleeper terrorist that he shoot himself right between the eyes with a revolver in his toilet. The revolver and the bullets were accurate. Minutes later John walks out of the toilet unharmed.
How can this be possible?

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

I look at you, you look at me I raise my right, you raise your left. What am I?

Can you move 2 matchsticks to form four equal sized squares.