RRB Lab Technician common mistakes
RRB Lab Technician · Understand the traps and how to avoid them.
In Mathematics, working the arithmetic forward from the question to the answer without checking the options, then running out of time on 100 questions in 90 minutes.
Candidates treat it like a school test where full working is required, but RRB papers reward option elimination and approximation; untimed practice at home hides the speed problem until the real exam.
What to do instead
Practise with a 45-second-per-question timer and drill shortcut techniques: elimination by unit digit, approximation to nearest round number, and plugging options back in. Keep a log of which method solved each question fastest.
Losing marks on simplification, percentage, ratio and average questions because of errors in BODMAS order and fraction-to-decimal conversion under pressure.
These are the highest-frequency quantitative topics, so they are attempted first and fast, and careless order-of-operations slips or misread fractions (1/8 as 0.125 not 0.18) go unchecked.
What to do instead
Memorise fraction-decimal-percentage equivalents up to twelfths and square roots up to 30. Before marking an answer, redo only the final operation mentally in reverse to verify.
In General Intelligence and Reasoning, attempting every seating arrangement, syllogism and puzzle in full instead of scanning the section first for quick wins.
The section mixes high-cost puzzles with fast items like coding-decoding, analogy, odd-one-out and series; candidates who go in order get stuck on one puzzle and lose 15 easy marks.
What to do instead
Adopt a two-pass strategy: first pass takes only coding-decoding, analogy, classification, series, direction and blood relation (roughly 60 seconds each); second pass returns to puzzles and non-verbal sets with remaining time.
Solving syllogisms and inequality questions by intuition or drawing mental pictures rather than applying Venn diagrams and the standard 'either-or' rules.
Candidates rely on real-world plausibility ('all cats are animals, so all animals are cats? no') instead of formal logic, and misjudge complementary pairs and 'possibility' cases.
What to do instead
Draw minimal Venn diagrams for every syllogism, test each conclusion against the minimal diagram, and separately test the possibility cases. For inequalities, chain the symbols and check each conclusion against the chain before answering.
In General Awareness, spending revision time on current affairs trivia while ignoring static topics that actually repeat: Indian polity articles, freedom movement dates, geography of India, and basic economics.
Coaching material and news apps overemphasise the last six months, but RRB General Awareness is dominated by static GK and a small, recurring set of current events tied to schemes, sports and awards.
What to do instead
Build a one-page revision sheet per static area: constitutional articles and amendments, major sessions of the Indian National Congress, rivers and their tributaries, national parks by state, and RBI monetary policy terms. Revise these weekly and add current affairs only from the last 12 months.
In General Science, answering physics and chemistry questions from everyday assumptions instead of recalling the actual definition or unit, for example confusing mass and weight or mixing up SI units.
School science is recalled vaguely, and candidates do not distinguish between similar-sounding terms (speed vs velocity, atomic number vs mass number, work vs power).
What to do instead
Maintain a two-column error notebook: term on the left, exact definition, formula and SI unit on the right. Add every question you got wrong by 'common sense' and revise the notebook before each mock.
In Basic Computer Knowledge, confusing RAM with ROM, primary with secondary storage, and hardware with software, and not being able to name file extensions and basic shortcut keys.
Candidates use computers daily but never study the vocabulary; the exam asks definitional questions that everyday use does not teach.
What to do instead
Learn one table covering memory types with volatility and examples, input/output devices, common extensions (.docx, .xlsx, .pptx, .pdf, .jpg), and standard shortcuts (Ctrl+C, Ctrl+V, Ctrl+Z, Ctrl+P, F5). Test yourself by covering one column.
In Laboratory Techniques and Procedures, describing a procedure without stating the correct specimen, anticoagulant, timing or safety step, such as giving a wrong tube colour or omitting universal precautions.
Candidates revise from procedure lists but not from the reasoning behind each step, so they cannot answer 'why is this done' or 'what happens if it is skipped' questions.
What to do instead
For every procedure, write five lines: specimen and container, anticoagulant, timing and temperature, critical step, and safety or rejection criterion. Rehearse these aloud so the sequence becomes automatic.
In Medical Laboratory Science, mixing up reference values, units and the clinical meaning of abnormal results, for example confusing normal haemoglobin ranges by sex or reading a raised ESR as diagnostic rather than supportive.
Values are memorised as isolated numbers without units or context, and candidates do not link a result to the disease pattern it suggests.
What to do instead
Build a reference-value card with units and adult male/female ranges for haemoglobin, RBC, WBC with differential, platelets, ESR, blood glucose, urea, creatinine and bilirubin. For each, add one line on what a high and a low value suggest, and review it before every mock.
In Medical Laboratory Science, guessing on microbiology and haematology identification questions (culture media, staining reactions, anaemia classification) instead of reasoning from the given clue.
These topics are memorisation-heavy, and candidates never learned to use the clue in the stem, such as Gram reaction, oxygen requirement or cell size, so they answer by vague familiarity.
What to do instead
Practise a decision-tree approach: for bacteria, ask Gram reaction, shape, oxygen requirement, then key biochemical or media clue; for anaemia, ask MCV first, then reticulocyte count. Write the tree once and apply it to 20 practice vignettes.