Most aspirants clear CDS by building Class 10 Maths speed, reading English daily and revising static GK with monthly current affairs. Start SSB preparation in parallel, because the written test only gets you to the interview.
6 months out
- Take one full CDS (II) paper set from our bank to find your weak paper.
- Maths: 1 hour a day. Finish arithmetic first (percent, ratio, time-work, speed), then geometry and mensuration, then algebra and trigonometry.
- English: read one editorial a day and note 10 new words; do 20 error-spotting questions daily.
- GK: cover NCERT Class 6–10 Science and History, then Polity basics; 45 minutes a day.
- Start running and push-ups for SSB and medical fitness.
3 months out
- Solve topic-wise previous-year questions from 2016 onward for every Maths and English topic.
- Add Geography and Economy; make one-page notes per chapter.
- Begin monthly current affairs and defence news (exercises, new equipment, appointments).
- Write one timed paper every week and check where you lost marks to negative marking.
Last 30 days
- Do a full three-paper mock on the exam timing (9 AM, 12:30 PM, 4 PM) at least twice a week.
- Revise your error notebook and GK one-pagers; no new books.
- Attempt only questions you can eliminate to 2 options or fewer; keep accuracy above 80%.
- Make sure you clear 20% in every paper; do not ignore your weakest paper.
After the written exam
- Start SSB prep at once: OIR reasoning, PPDT stories, TAT/WAT/SRT practice, and a clear self-description.
- Register on joinindianarmy.nic.in if IMA or OTA is your first choice.
Books and resources
- NCERT Maths Class 6–10 — The CDS Maths paper is at Class 10 level; NCERT covers every topic.
- R.S. Aggarwal – Quantitative Aptitude — Lots of arithmetic practice at the right speed.
- Wren & Martin – High School English Grammar — Grammar rules behind error-spotting and sentence-improvement questions.
- Word Power Made Easy (Norman Lewis) — Builds vocabulary for synonyms, antonyms and idioms.
- NCERT Science and Social Science Class 6–10 — Most static GK questions come from this level.
- Lucent's General Knowledge — Quick revision of history, geography, polity and science facts.
- Previous CDS papers (2016–2025) — Shows the real question style and repeated topics.
Mistakes to avoid
- Guessing wildly; one-third negative marking adds up fast over 340 questions.
- Skipping Maths practice because it is 'only Class 10'; speed is the real test.
- Ignoring the 20% minimum in each paper.
- Studying only for the written test and leaving SSB preparation for later.
- Neglecting physical fitness and eyesight, which can fail you at the medical.