Solve the mathematical equation in the picture below.

Who always enjoys poor health?

A mad serial killer kidnaps people and forces them to play the game of 2 pills with them, In this game, there are pills in the table and one of them is normal pill while the other one is deadly poisonous.
The victim will choose one pill and the killer will pick the other pill and both simultaneously will swallow the pill with water.
victim dies every time.

One day the serial killer kidnaps the Joseph and forces him to play the same game with him.

Joseph solves the mystery of the two pills and remains alive.

Explain?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

What has one letter and starts with an E?

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

As we know that white starts the game of chess. Can you find the scenario shown in the picture below is possible when all the white pieces are at the original place while the black pawn is not as in the below picture?

They are three errirs in this question. Can you find them?

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.