What has no start, end, or centre?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

With the following rules:

(A) White can make up to 10 legitimate moves until all kings are checkmate.
(B) White can take any black piece except the king.
(C) The White King cannot be in check position at any time of the game.

Can you checkmate all kings in less than 10 moves?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

You have two jars of chocolates labelled as P and Q. If you move one chocolate from P to Q, the number of chocolates on B will become twice the number of chocolates in A. If you move one chocolate from Q to P, the number of chocolates in both the jars will become equal.

Can you find out how many chocolates are there in P and Q respectively?

If you were to put a coin into an empty bottle and then insert a cork into the neck, how could you remove the coin without taking out the cork or breaking the bottle?

The captain of a ship is telling you an interesting story and then poses a question. He says, “I have travelled the oceans far and wide. One time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly. Can you tell me how that was possible?”

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

Paul's height is six feet, he's an assistant at a butcher's shop and wears size 9 shoes. What does he weigh?