National 9th-grade civil service computer positions past exam questions · General Computer Science · Information Security 2015–2026
Solve 480 past exam questions from 2015–2026 for the two major subjects of the national 9th-grade computer administration exam (General Computer Science and Information Security) through 20-minute CBTs for each subject. The questions and final answers are exactly as released by the Ministry of Personnel Management. Upon submission, your score and whether you failed a subject immediately appear, and every question includes an explanation.
Practice solving 480 questions from 12 years within 20 minutes per subject
Criteria for selecting weak subjects based on subject scores by year
Past questions for the national 9th-grade civil service computer science exam
● National 9th-grade Civil Service Computer Position Past Exam CBT · 2015~2026
Two major subjects, 20 minutes per subject
The 2015~2026 past questions for Computer Fundamentals and Information Security, the specialized subjects for the National 9th-grade civil service IT exam (Computer Development track), have been converted into year-by-year CBTs. The actual exam includes Korean, English, Korean History, and two specialized subjects, with 100 questions to be solved together in 100 minutes. Since there is no separate time limit for each subject, 20 minutes is used as the average per subject. This is a practice tool for completing Computer Fundamentals, which contains many coding questions, within 20 minutes.
480questions
24lessons
60 secondsper question
All questionsExplanations
First Mission
If this is your first time, start by measuring your current level with two subjects from 2026.
1
Take 2026 Computer General in real-test mode for free—20 questions in 20 minutes. That's the actual exam's 100 minutes divided among five subjects.
2
8 questions or moreWe count the number of questions instead of scores. Since this is an exam with no passing score, once you get past the minimum required, your mission is to get “one more question than last time.”
3
If you continue with Information Security from the same year, freethe two subjects together take 40 minutes for 40 major-subject questions. A link to Information Security will appear on the Computer Fundamentals results screen.
Scores accumulate in this browser for each class, and when you reopen the same class, whatever you were short of last time becomes the next mission.
2023 Computer Science, Question 8. The code is indented exactly as it appears on the exam paper.
Structure
Subject
Year
Questions
Time
General Computer Science
2015–2026 (12 sessions)
20 per session
20 minutes
Information Security Theory
2015–2026 (12 sessions)
20 per session
20 minutes
24 lessons · 480 questions. Starting in 2026, they are arranged from newest to oldest. Only national civil service exams are included; local government and Seoul Metropolitan Government exams, as well as information security-track subjects (Network Security and Information Systems Security), are not included.
Solving method
Exam Mode
It will be submitted automatically after 20 minutes. Your score, whether you received a failing grade (below 40 points), and the time taken will be displayed. Since Grade 9 open recruitment candidates are accepted in order of highest scores within the number of available positions, only whether you received a failing grade is determined instead of using a fixed passing score.
Study Mode
Without a time limit, the correct answer and explanation appear immediately when you select an option.
Notifications during the quiz
The remaining questions are displayed one per line when half the time has passed and 2 minutes before the deadline. You can turn this off on the start screen.
Retry
Re-solve only the questions you got wrong in study mode. If you grade the same lesson again, the difference from your previous score will also be shown.
Record
Your answers in progress, remaining time, and grading records are saved in this browser. They will not carry over to other devices.
This is the grading screen using the sample answers.
Explanation
All 480 questions include explanations. The basis for the correct answer is given first, followed by an assessment of each incorrect option (for combination-type questions, ㄱ–ㄹ individually). For calculation questions involving number systems, complements, scheduling, subnetting, and similar topics, the process is shown line by line. For the 28 general computer science code questions (C, Python, Java, and SQL), the values and output are shown by following the execution order.
For the information security law questions, I compared the provisions in effect on the exam date with the provisions currently in effect. For choices whose conclusions differ under the current standards because laws or standards changed after the exam, I noted them separately as “Legislative Amendment” directly below the correct answer. There are five information security questions in total (one each from 2015, 2016, 2020, 2022, and 2023).
The explanations were written by AI and have not yet been reviewed by an expert. I will accept reports of errors in the explanations as questions during class and correct them.
Question 19 of Information Security Theory from 2015. The penalty for leaking resident registration numbers (Article 34-2 at the time) was eliminated in the 2023 amendment and consolidated into the penalty under Article 64-2.
Things to know
The questions and answers are exactly as published by the Ministry of Personnel Management and Innovation. For question 17 of the 2023 General Computer Science exam, the final answer includes both ① and ② as correct answers, so either choice is correct. The explanations note the circumstances surrounding the two questions for which the final answers may be subject to disagreement (question 18 of the 2023 General Computer Science exam and question 6 of the 2025 General Computer Science exam).
The reference date for the laws in the explanations is the date of each exam. The 2020 exam was postponed due to COVID-19 and held on July 11.
Although the question-setting approach for Korean and English changed beginning in 2025, General Computer Science and Information Security have remained the same across all 12 years: 20 questions with four choices each.
Diagrams such as circuit diagrams, trees, and graphs have been converted into text and tables.
You can solve the 2026 Computer Science Fundamentals and Information Security questions for free.
Question Source
Ministry of Personnel Management, 2015–2026 National Civil Service Grade 9 Open Competitive Recruitment Written Examination Computer Science and Information Security Questions and Final Answers (No restrictions on the scope of use under the Public Data Portal). The explanations and CBT were created by Inflearn and are not affiliated with the Ministry of Personnel Management.
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Who is this course right for?
A computer science exam candidate who has finished studying the major theories and should now solve past exam questions under timed conditions
Test takers who spend a lot of time on code tracing and calculation questions
