Defence: NDA / CDS / AFCAT Exam Survival Guide

NDA & NA (UPSC)

Pattern (official): Two papers—Mathematics (300, 2.5 h) and GAT (600, 2.5 h); objective with negative marking. SSB after written. 

Must-do (80/20)

• Math: algebra, trig, coordinate, calculus basics, vectors, statistics.
• GAT: English (grammar/usage/RC), GK (history, polity, geo, science), current events.

Time split

• Math: 3 passes—singles → medium → tough; cap any item @ 90s.
• GAT: English harvest → science/polity → history/geo → CA.

Last-48h

• 2 math papers timed; 1 GAT paper; formula ring + GK one-pager.

CDS (UPSC)

Pattern (official): For IMA/INA/AFA—English (100, 2h) + GK (100, 2h) + Elementary Maths (100, 2h); OTA—English + GK only; negative marking (1/3). SSB follows. 

Must-do (80/20)

• Math: arithmetic/number theory, geometry/trig, algebra; speed math.
• English: vocab-in-context, error-spot, ordering, RC.
• GK: defence/current, polity, geo, sci, economy.

Last-48h

• 1 full set (all three for IMA/INA/AFA or two for OTA); revise CA (last 6–9 mo).

AFCAT (IAF)

Pattern (official): AFCAT: 100 Q, 300 marks, 2 h, −1 per wrong; sections—GA, English, Numerical Ability, Reasoning & Military Aptitude. EKT (for tech) 50 Q, 150 marks, 45 min. 

Must-do (80/20)

• Math/NA: %/ratio/avg, SI/CI, TSD, series.
• English: error-spot, vocab, RC.
• GA/Defence: ranks, commands, aircraft/missiles, space & science.
• Reasoning/MAT: series, analogies, spatial.

Last-48h

• 1 AFCAT mock + (if tech) 1 EKT; GA defence glossary; speed-calc drills.

Shared “quick frames” for all three

• TAUSL for any chart/data; units first.
• Elimination heuristics: kill extremes, check qualifier words (only/always).
• GK/Defence: prefer official sources over coaching summaries.