IAF Group C common mistakes
IAF Group C · Understand the traps and how to avoid them.
Reading a reasoning puzzle once, then answering from memory of the question stem instead of re-checking the exact conditions (e.g., 'only if', 'all except', 'at least') before marking the option.
Under a timed, negative-marking paper, candidates skim to save seconds and their brain stores a simplified version of the conditions, so the option chosen matches the simplified version rather than the printed one.
What to do instead
Before finalising each reasoning answer, underline or mentally re-read the operative words in the stem and verify the chosen option against each stated condition one by one; for arrangement and blood-relation items, do a 5-second consistency check of the final arrangement against every clue.
Solving seating-arrangement, ranking, and direction-sense problems entirely in the head instead of drawing a quick diagram, then losing track of left/right or facing directions.
These questions look small enough to hold in working memory, but the number of constraints exceeds what most people can track reliably, and left/right reverses when a person faces south or outward.
What to do instead
Always sketch: a row of blanks for linear arrangements, a circle with arrows for facing direction, and a compass cross for direction sense. Mark facing direction on every seat before placing anyone, and re-derive the answer from the diagram, not from memory.
In numerical aptitude, computing the answer correctly but then marking a distractor because the question asked for a ratio, percentage, or unit different from the one just calculated.
The arithmetic consumes attention, and the final conversion step ('find the ratio', 'what percent', 'in metres') gets dropped; exam setters deliberately place the pre-conversion value among the options.
What to do instead
Circle the demanded quantity in the question before starting the calculation and write the unit/format beside your working. After computing, compare your value against the options only after performing the requested conversion, and reject any option that matches an intermediate value.
Attempting every quantitative question in order, spending several minutes on one hard problem, and leaving easy later questions (percentages, averages, simplification) unattempted.
The paper is ordered by topic, not difficulty, and the instinct to 'finish the section' overrides scoring strategy; one stubborn question can consume the time of four easy ones.
What to do instead
Do two passes: first pass solves only questions recognised within about 30 seconds, second pass returns to the rest. Set a hard per-question cap (roughly 60-90 seconds) and move on when it is hit, since each question carries equal marks.
In General English, choosing an option because it 'sounds right' in a fill-in-the-blank or sentence-improvement item without checking subject-verb agreement, preposition collocation, or tense consistency across the whole sentence.
Spoken-English intuition is fast but unreliable for written grammar, and distractors are built to sound plausible in isolation while breaking a rule elsewhere in the sentence.
What to do instead
For each English item, run a fixed checklist: subject-verb agreement, tense sequence, article/preposition collocation, pronoun reference, and parallel structure. Eliminate options that fail any check before selecting, and read the completed sentence silently once to confirm it is grammatical.
In reading comprehension and cloze passages, selecting an option that repeats words from the passage rather than one that answers the question, and answering detail questions from general knowledge instead of the text.
Keyword matching feels safe and is fast, and candidates trust background knowledge on familiar topics; both habits are exactly what distractors are designed to exploit.
What to do instead
Read the question first, then locate the relevant sentence and answer strictly from it, paraphrasing in your own words before looking at the options. Reject options that are true in general but not stated in the passage, and treat exact word repetition as a warning sign rather than evidence.
In General Awareness, guessing between two similar-sounding options (dates, articles of the Constitution, awards, appointments) without a basis, or relying on outdated static facts for current-affairs questions.
Static GK is revised from old notes, while current affairs change every month; under time pressure the two similar options feel equally likely and the candidate picks randomly instead of using elimination.
What to do instead
Maintain a rolling 6-12 month current-affairs log updated monthly, and for static GK anchor facts with mnemonics or timelines rather than isolated dates. In the exam, eliminate on any verifiable detail (which country, which year, which article number) before guessing, and skip pure guesses if negative marking applies.
In the trade/post-specific technical section, answering from general textbook memory without applying the specific rule, standard, or procedure the question describes, and confusing similar technical terms or abbreviations.
Technical sections test applied knowledge of the specific post's rules and terminology, and candidates revise broad theory while skipping the exact definitions, limits, and standard procedures that questions target.
What to do instead
Build a one-page glossary of the post's key terms, abbreviations, limits, and standard procedures, and revise it repeatedly. For each practice question, write down which specific rule it tests and where that rule comes from, so recall is tied to the source rather than to vague familiarity.
In computer knowledge, mixing up similar-sounding concepts (RAM vs ROM, primary vs secondary storage, file extension vs file type, copy vs cut, save vs save-as) and answering shortcut-key questions from habit rather than certainty.
Basic computer questions look trivial, so candidates skip systematic revision; everyday clicking does not build precise knowledge of shortcuts, menus, and terminology, and options are designed as near-pairs.
What to do instead
Revise from a structured table: memory types with volatility and examples, storage devices with typical capacities, common file extensions, and standard shortcut keys for Windows and office suites. Practise the shortcuts hands-on once, and for each option ask what the alternative term would be, to confirm the distinction.
In office procedures, answering drafting and correspondence questions by general impression of what a letter 'should' look like, instead of the prescribed format, hierarchy of authority, and record-keeping sequence.
Office procedure is learned on the job through local practice, which varies by office, while the exam expects the standard prescribed procedure; candidates therefore apply their own office's habits.
What to do instead
Study the standard procedure as a sequence: receipt and diary entry, marking to the appropriate officer, draft preparation, approval level, dispatch, and filing, and learn which officer has authority at each stage. For format questions, memorise the prescribed order of parts of a formal letter and note-taking, and practise drafting one specimen of each document type.