Hello,

UPSC Civil Service Examination is conducted in three stages namely preliminary, mains and interview, when it comes to prelims it is MCQs based exam, it has two papers, each one is conducted for two hours, and each consists of 200 marks, its numbers ain't added to final list, you just need to score the required cut offs against your respective category.

Out of the two papers in preliminary examination,  first is general studies paper I which has a total of 100 questions, and for each correct answer two marks are awarded, and in case of incorrect attempt one-third of total mark is deduced that is 0.66 marks in case of each wrong answer,

and second is general studies paper II also called CSAT which has 80 questions, each carrying 2.5 marks, in case of wrong attempt, 0.83 marks is deduced, the same method of deduction of 0.33 of total marks is applicable here also, however this paper is only qualifying by nature, and you need to score only 33% of total allotted marks, that is 66 marks out of 200 marks.