Attempting the
civil services preliminary exam is a different ball game from tackling the main civil services exam. In the preliminary exam there is negative marking, and the civil services exam question paper is a booklet consisting of many pages. There are 100 questions in civil services exam Paper I and 80 in civil services exam Paper II, with four choices under each question. The time allotted is two hours for each of the civil services exam papers. One may have to read 20 - 25 pages of the question booklet, and to mark the correct answer, one has to read the question and the four choices. Thus, it is not possible to read all the questions and the answers more than once, and also one has to attempt all the questions in civil services exam.
Therefore, you have to begin attempting the questions right from the start. As soon as you read the first question and are sure about the correct answer, attempt it immediately by blackening the correct circle in the answer sheet. Go on attempting all the questions to which you know the answers for sure. It is only when you are not sure about the one correct answer that you should leave that question to be re-read and re-thought later on. If you feel that there could be two possible correct answers among the four given choices, you should put a small mark with pencil in the two circles corresponding to these in the answer sheet.
Say, for question number 7, you think either B or C could be the correct choice and therefore you want to think over it again later on, but you also feel that B could be a better than C, then mark 1 with pencil against B and mark 2 in pencil against C in the answer sheet. The marking of 1 or 2 in the answer sheet should be done softly and with a blunt pencil, as later on these markings have to be erased. Thus, the circle marked 1 is the better choice. Now, out of 100 questions, there may be 15 - 25 questions about which you might be in two minds about the correct choice.
There might be 10 or 15 questions about which you have no idea, and, due to negative marking, there is no point in attempting such questions, so forget these. These 15 - 25 questions which you have narrowed down to the two answers must be attempted. In the end, if you are left with 15 - 20 minutes, then you should go back to the question booklet and again read the question and the two probable answers and try to think about which one is the better and blacken the circle with the better answer. But suppose you are left with only four or five minutes to attempt these 15 - 20 questions, instead of going back to the question booklet, you should straightaway blacken the circles marked 1.
You must attempt all such questions civil services exam where you have narrowed down to the two answers, because the ratio of negative marking is 1:3. If you mark one correct answer you get two marks whereas you lose two marks if you mark three wrong answers. The theory of probability says that, out of 20 such questions, you will happen to mark ten correct answers, and, therefore, you will gain despite the negative marking in civil services exam.
To put it in another way, if you attempt four such questions out of which one is correct and three are wrong, there is still no loss as such. And in the end, don't forget to erase the pencil markings from the answer sheet.