GAT General Math Tip no.1: 2 to 3 concepts are tested
When you are solving a math problem beware of the fact that if you get your answer too easily it is not the correct answer. Examiners are never going to give you easy questions and if you are finding it easy to solve the problem there is a high probability that it is not the answer. Every question requires you to know two concepts. I would like to explain it with the help of an example.
Question: Multiply all the numbers from -100 to 100
This might seem to be a very difficult question and most students would think that a lot of calculation would be needed by in reality it is the easiest question you will see on the exam.
The two concepts you should know about this question are multiplication and the properties of 0
The mid-value of this range is 0 and even if you multiply 0 by a billion the answer would remain 0, so the answer would be 0.