People put me on the table and cut me but do not eat me. What am I?

In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?

Can you identify the famous TV character from the rebus below?

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?

What is both possible and impossible at the same time?

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

How can one talk without saying a single word?

Which is faster, Heat or Cold ? Explain.

You have a 12 liters jug full of water. You have two empty 8 liters and 5 liters jug. How can you divide the water into two equal parts using these jugs?