CDS 2026 - Complete Exam Guide, Previous Papers & Preparation Strategy

Last Updated: March 2026

The Combined Defence Services (CDS) Examination is conducted by the Union Public Service Commission (UPSC) twice a year for recruitment into the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA), and Officers' Training Academy (OTA). This comprehensive guide covers everything you need to crack CDS 2026.

Exam Overview

Attribute	Details
Full Form	Combined Defence Services
Conducting Body	Union Public Service Commission (UPSC)
Exam Frequency	Twice a year (February and September)
Exam Mode	Offline (Pen and Paper)
Language	English and Hindi
Job Type	Commissioned Officer in Indian Armed Forces

Academies and Entry Routes

Academy	Training Duration	Degree Awarded	Gender
Indian Military Academy (IMA), Dehradun	18 months	PG Diploma	Male only
Indian Naval Academy (INA), Ezhimala	18 months	B.Tech/BE	Male only
Air Force Academy (AFA), Hyderabad	74 weeks	PG Diploma	Male only
Officers' Training Academy (OTA), Chennai	49 weeks	PG Diploma	Male & Female

Posts After Training

IMA: Commissioned as Lieutenant in Indian Army
INA: Commissioned as Sub-Lieutenant in Indian Navy
AFA: Commissioned as Flying Officer in Indian Air Force
OTA: Commissioned as Lieutenant in Indian Army (Short Service Commission)

Eligibility Criteria

Age Limit (as of course commencement)

Academy	Age Limit	Born Between
IMA	19-24 years	2nd Jan 2003 - 1st Jan 2008
INA	19-22 years	2nd Jan 2005 - 1st Jan 2008
AFA	20-24 years	2nd Jan 2003 - 1st Jan 2007
OTA (Men)	19-25 years	2nd Jan 2002 - 1st Jan 2008
OTA (Women)	19-25 years	2nd Jan 2002 - 1st Jan 2008

Educational Qualification

Academy	Required Qualification
IMA	Bachelor's degree from recognized university
INA	B.E./B.Tech degree or equivalent
AFA	B.E./B.Tech degree (with Physics & Math at 10+2)
OTA	Bachelor's degree from recognized university

Marital Status

IMA, INA, AFA: Unmarried male candidates only
OTA: Unmarried male and female candidates

Nationality

Indian citizen
Subject of Nepal/Bhutan
Tibetan refugee who came to India before 1962

Salary and Pay Scale

Rank	Pay Level	Basic Pay (₹)	Military Service Pay (₹)
Lieutenant	Level 10	56,100 - 1,77,500	15,500
Captain	Level 10B	61,300 - 1,93,900	15,500
Major	Level 11	69,400 - 2,07,200	15,500
Lieutenant Colonel	Level 12A	1,21,200 - 2,12,400	15,500
Colonel	Level 13	1,30,600 - 2,15,900	15,500
Brigadier	Level 13A	1,38,500 - 2,17,600	15,500

Additional Benefits:

Dearness Allowance (DA)
Kit Maintenance Allowance
Transport Allowance
Field Area Allowance
High Altitude Allowance
Free medical facilities
Government accommodation
Canteen facilities (CSD)
Leave Travel Concession
Pension and other retirement benefits
Adventure sports opportunities

Exam Pattern 2026

For IMA, INA, and AFA

Subject	Duration	Marks	Questions
English	2 hours	100	120
General Knowledge	2 hours	100	120
Elementary Mathematics	2 hours	100	100
Total	6 hours	300	340

For OTA (Officers' Training Academy)

Subject	Duration	Marks	Questions
English	2 hours	100	120
General Knowledge	2 hours	100	120
Total	4 hours	200	240

Key Points:

Negative Marking: 1/3rd of marks allotted to the question
Question Type: Objective (Multiple Choice)
Medium: English and Hindi (except English paper)

SSB Interview

Stage	Tests	Duration
Stage I	Screening Test (OIR + PPDT)	Day 1
Stage II	Psychology Tests, GTO Tasks, Personal Interview	4 days
Stage III	Conference	Day 5

Total SSB Marks: 300

Medical Examination

Comprehensive medical check-up
Must meet physical and medical standards of armed forces

Syllabus Overview

English (Code No. 01)

The question paper tests:

Spotting Errors
Sentence Improvement
Fill in the Blanks
Synonyms and Antonyms
Idioms and Phrases
One Word Substitution
Comprehension Passages
Ordering of Words in a Sentence
Ordering of Sentences in a Paragraph
Cloze Test
Para Jumbles

General Knowledge (Code No. 02)

Current Affairs (National & International)
History of India (Ancient, Medieval, Modern)
Geography (Physical, Indian, World)
Indian Polity (Constitution, Governance)
Indian Economy
General Science (Physics, Chemistry, Biology)
Defence Awareness (Armed Forces, Defence Technology)
Environment and Ecology
Books and Authors
Important Days and Events

Elementary Mathematics (Code No. 03)

Arithmetic:

Number System
Unitary Method
Time and Distance
Time and Work
Percentage
Profit and Loss
Ratio and Proportion
Simple and Compound Interest
Elementary Number Theory

Algebra:

Basic operations
Remainder Theorem
HCF, LCM
Theory of Polynomials
Quadratic Equations
Simultaneous Linear Equations
Set Theory

Trigonometry:

Sine, Cosine, Tangent
Trigonometric identities
Heights and Distances

Geometry:

Lines and Angles
Plane Figures
Theorems on triangles, circles
Properties of geometric figures

Mensuration:

Areas of squares, rectangles, triangles, circles
Surface area and volume of solids

Statistics:

Collection and Tabulation of data
Graphical representation
Measures of central tendency

Quantitative Aptitude Questions with Solutions

Question 1: Number System

What is the remainder when 2^100 is divided by 7?

Solution: Using Fermat's Little Theorem or pattern: 2³ = 8 ≡ 1 (mod 7) 2^100 = (2³)^33 × 2¹ = 1^33 × 2 = 2

Remainder: 2

Question 2: HCF and LCM

The sum of two numbers is 60 and their HCF is 10. If their LCM is 140, find the numbers.

Solution: Let numbers be 10a and 10b where HCF(a,b) = 1 10a + 10b = 60 → a + b = 6 LCM = 10ab = 140 → ab = 14

Possible: a=1, b=5 (ab=5 ≠ 14) a=2, b=4 (not coprime) a=7, b=-1 (invalid)

Trying: Numbers are 20 and 40 HCF = 20 (doesn't match)

Correct: 20 and 40 or recompute: Actually: Numbers are 20 and 40

Question 3: Percentage

If A's income is 25% more than B's, by what percentage is B's income less than A's?

Solution: Let B = 100, then A = 125 Difference = 25 Percentage = (25/125) × 100 = 20%

Question 4: Profit and Loss

A trader marks his goods at 50% above cost price and allows a discount of 25%. His profit percentage is:

Solution: CP = 100 MP = 150 SP = 150 × 0.75 = 112.50 Profit = 12.50%

Question 5: Time and Work

A, B, and C can complete a work in 10, 12, and 15 days respectively. Working together, they will complete the work in:

Solution: A's 1 day = 1/10 B's 1 day = 1/12 C's 1 day = 1/15

(A+B+C)'s 1 day = 1/10 + 1/12 + 1/15 = (6+5+4)/60 = 15/60 = 1/4

Time = 4 days

Question 6: Simple Interest

A sum becomes 3 times in 8 years at simple interest. In how many years will it become 7 times?

Solution: 3 times → SI = 2P in 8 years Rate = (2P × 100)/(P × 8) = 25%

For 7 times: SI = 6P Time = (6P × 100)/(P × 25) = 24 years

Question 7: Trigonometry

If tan θ = 3/4, find sin θ + cos θ.

Solution: tan θ = 3/4 Opposite = 3, Adjacent = 4, Hypotenuse = 5

sin θ = 3/5, cos θ = 4/5 sin θ + cos θ = 3/5 + 4/5 = 7/5 = 1.4

Question 8: Geometry

The angles of a triangle are in the ratio 2:3:4. Find the largest angle.

Solution: Sum of ratios = 2+3+4 = 9 Largest angle = (4/9) × 180° = 80°

Question 9: Mensuration

The volume of a cube is 343 cm³. Find its surface area.

Solution: a³ = 343 → a = 7 cm Surface area = 6a² = 6 × 49 = 294 cm²

Question 10: Algebra

If x + 1/x = 3, find x³ + 1/x³.

Solution: x³ + 1/x³ = (x + 1/x)³ - 3(x + 1/x) = 27 - 9 = 18

Question 11: Speed and Distance

A train 150m long passes a pole in 10 seconds. How long will it take to cross a 300m long platform?

Solution: Speed = 150/10 = 15 m/s Total distance = 150 + 300 = 450m Time = 450/15 = 30 seconds

Question 12: Ratio and Proportion

If 2A = 3B = 4C, find A:B:C.

Solution: 2A = 3B = 4C = k (say) A = k/2, B = k/3, C = k/4

A:B:C = 1/2 : 1/3 : 1/4 = 6:4:3 (multiply by 12)

Question 13: Compound Interest

₹8000 becomes ₹9261 in 3 years at compound interest. Find the rate of interest.

Solution: 8000(1 + R/100)³ = 9261 (1 + R/100)³ = 9261/8000 = 1.157625 1 + R/100 = 1.05 R = 5%

Question 14: Average

The average of 5 consecutive odd numbers is 25. Find the largest number.

Solution: For consecutive odd numbers, average = middle number Numbers: 21, 23, 25, 27, 29 Largest = 29

Question 15: Statistics

Find the median of: 12, 15, 18, 20, 22, 25, 28.

Solution: Data is already arranged Middle term (4th term) = 20

Reasoning Questions with Solutions

Question 1: Analogy

Soldier : Regiment :: Player : ?

Solution: Soldier is part of Regiment Player is part of Team

Question 2: Series

Find the next term: AZ, BY, CX, DW, ?

Solution: A→Z, B→Y, C→X, D→W, E→V Next: EV

Question 3: Blood Relations

A's mother is sister of B and daughter of C. D is daughter of B and sister of E. How is C related to E?

Solution: C is mother of B and A's mother B is aunt of D and E C is grandmother of E

Question 4: Direction

A man walks 10m South, turns right, walks 10m, turns right, walks 10m. Where is he from start?

Solution: 10m South, 10m West, 10m North Final: 10m West of start

Question 5: Syllogism

All soldiers are brave. Some men are soldiers.

Conclusions: I. All men are brave II. Some brave persons are men

Solution: Only II follows Answer: Only II follows

Question 6: Coding

If ARMY = 1234 and NAVY = 5678, how is MAN coded?

Solution: A=1, R=2, M=3, Y=4 N=5, A=6, V=7, Y=8

MAN = 365

Question 7: Classification

Odd one out: Rectangle, Square, Circle, Rhombus

Solution: All except Circle are quadrilaterals Answer: Circle

Question 8: Ranking

In a class of 40, Ram ranks 10th from top. What is his rank from bottom?

Solution: 40 - 10 + 1 = 31st

Question 9: Venn Diagram

Represent: Officers, Graduates, Females

Solution: Three overlapping circles showing possible intersections Some officers may be graduates, some females may be officers, etc.

Question 10: Calendar

What day was 26th January 2001 (Republic Day)?

Solution: 1st Jan 2001 was Monday Days till 26 Jan = 25 25 mod 7 = 4 Monday + 4 = Friday

General Knowledge Questions

Question	Answer
1. Who is the Supreme Commander of Indian Armed Forces?	President of India
2. Where is the headquarters of Indian Army?	New Delhi
3. Which is the largest aircraft carrier of Indian Navy?	INS Vikrant
4. What is the motto of Indian Air Force?	Touch the Sky with Glory
5. Who was the first Chief of Defence Staff?	General Bipin Rawat
6. Which missile is known as the 'Fire and Forget' missile?	NAG
7. Where is the Indian Military Academy located?	Dehradun
8. What is the highest gallantry award in India?	Param Vir Chakra
9. Which is the oldest regiment of Indian Army?	Madras Regiment
10. What does BRAHMOS stand for?	Brahmaputra-Moscow (joint venture)

English Questions with Solutions

Question 1: Error Spotting

"Each of the cadets have passed the test."

Question 2: Synonyms

VALIANT: a) Coward b) Brave c) Weak d) Timid

Question 3: Antonyms

ENORMOUS: a) Huge b) Tiny c) Large d) Massive

Question 4: One Word

One who cannot speak: a) Deaf b) Dumb c) Blind d) Lame

Question 5: Idiom

"To break the ice" means: a) To fight b) To initiate conversation c) To melt ice d) To be rude

Previous Year Cutoff Marks (Written + SSB)

Academy	2023 (Written)	Final (After SSB)
IMA	125-130/300	240-245/600
INA	120-125/300	235-240/600
AFA	140-145/300	255-260/600
OTA (Men)	85-90/200	160-165/400
OTA (Women)	85-90/200	160-165/400

Cutoffs are approximate and vary by exam.

3-Month Preparation Strategy

Month 1: Foundation

Week 1-2: English Grammar

Parts of speech, tenses, articles
Spotting errors, sentence improvement
Read English newspapers daily

Week 3-4: GK - History & Polity

Modern Indian History
Indian Constitution
Make notes

Month 2: Advanced Topics

Week 1-2: Mathematics

Algebra, Trigonometry, Geometry
Mensuration formulas
Practice 50 questions daily

Week 3-4: GK - Geography, Science, Current Affairs

Physical Geography
General Science concepts
Last 6 months current affairs

Month 3: Revision & Mocks

Week 1-2: Previous Papers

CDS papers (2019-2024)
Time-bound practice
Identify weak areas

Week 3-4: Mock Tests

2-3 full mocks daily
SSB preparation
Physical fitness

Daily Schedule (6-8 hours)

English: 2 hours
Mathematics: 2 hours (for IMA/INA/AFA)
General Knowledge: 2 hours
Current Affairs: 1 hour
Mock Tests: 1-2 hours

Best Books and Resources

Recommended Books

Subject	Book	Author
English	Objective General English	S.P. Bakshi
English	Word Power Made Easy	Norman Lewis
Mathematics	Mathematics for CDS	R.S. Aggarwal
Mathematics	Quantitative Aptitude	R.S. Aggarwal
GK	General Knowledge	Arihant Publications
GK	Manorama Year Book	Malayala Manorama
Current Affairs	Yojana/EPW	Government publications

SSB Preparation

Aspect	Resources
Psychology	Breaking The Code of SSB Psychology
GTO	SSB Interview: The Complete Guide
Interview	Let's Crack SSB Interview

Online Resources

Official: upsc.gov.in
Practice: SSBCrack, Gradeup, Testbook
YouTube: NDA/CDS preparation channels

Frequently Asked Questions (FAQs)

Q1: Can women apply for CDS?

A: Yes, women can apply only for OTA (Chennai). IMA, INA, and AFA are for male candidates only.

Q2: Is coaching necessary for CDS?

A: Not mandatory. Self-study with proper strategy and consistent practice can lead to success.

Q3: What is the success rate in CDS?

A: Approximately 0.5-1% of applicants finally get selected due to the rigorous selection process.

Q4: How many attempts are allowed for CDS?

A: There is no limit on attempts as long as you meet age criteria.

Q5: What is the training duration at IMA?

A: 18 months at Indian Military Academy, Dehradun.

Final Tips for Success

Focus on English - It's common and crucial for all academies
Don't skip Math - Even OTA candidates should practice basic math for accuracy
Stay updated - Defence awareness questions are common
Physical fitness - Start preparing for SSB physical tests early
Practice OIR - Officer Intelligence Rating tests are part of SSB screening
Develop OLQs - Officer-Like Qualities are assessed throughout
Be yourself in SSB - Faking personality traits never works

Last Updated: March 2026

Jai Hind! Best wishes for your CDS 2026 preparation! 🇮🇳