Eight of us go fourth, not back, to protect our king from an attack. What are we?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches

There are two insects on a tile. Insect X is sitting on one side of the tile (point A) and Insect Y is sitting opposite on the other side of the tile (point B). Now both of them decide to change their position and thus X starts crawling to point B and Y starts crawling to point A. When they meet and pass each other in between, X takes 20 seconds to reach B and Y takes just 5 seconds to reach A.

Can you calculate the total time each of the insects took to change their positions?

What type of tree can I carry in my hand?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

Suppose we lay down two cups in front of you. One of the cups is filled with tea and the other one with coffee. Now we ask you to take a spoonful of tea and mix it with the coffee. At this moment, the coffee cup has a mixture of tea and coffee. You have to take that mixture (spoonful) and add it back to the tea.

Can you now tell if the cup of coffee has more tea or the cup of tea has more coffee?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?