🔢 Number Series
Trick: Find the pattern between consecutive terms first — differences, ratios, squares. If differences look random, check the differences OF the differences.
Q12, 6, 12, 20, 30, ?Show answer ▾
✔ Answer: 42
Differences are 4, 6, 8, 10 — increasing by 2. Next difference is 12, so 30 + 12 = 42. (These are also n²+n: 2, 6, 12, 20, 30, 42.)
Q23, 9, 27, 81, ?Show answer ▾
✔ Answer: 243
Each term is multiplied by 3. 81 × 3 = 243. Whenever terms grow fast, test ratios before differences.
Q31, 4, 9, 16, 25, ?Show answer ▾
✔ Answer: 36
These are perfect squares: 1², 2², 3², 4², 5². Next is 6² = 36. Memorise squares to 25 and cubes to 12 — series questions love them.
Q45, 11, 23, 47, ?Show answer ▾
✔ Answer: 95
Each term is (previous × 2) + 1: 5→11, 11→23, 23→47, 47→95. If ×2 alone doesn't fit, try ×2 ± a small constant.
🔤 Letter Series
Trick: Convert letters to positions (A=1 … Z=26). The alphabet with numbers written under it is the first thing to scribble on your rough sheet.
Q5A, C, F, J, O, ?Show answer ▾
✔ Answer: U
Positions are 1, 3, 6, 10, 15 — gaps of +2, +3, +4, +5. Next gap is +6: 15 + 6 = 21 = U.
Q6Z, X, U, Q, ?Show answer ▾
✔ Answer: L
Positions 26, 24, 21, 17 — gaps of −2, −3, −4. Next gap is −5: 17 − 5 = 12 = L.
Q7AZ, BY, CX, ?Show answer ▾
✔ Answer: DW
First letters go forward (A, B, C, D) while second letters go backward (Z, Y, X, W). Paired-opposite series like this are very common.
🔐 Coding–Decoding
Trick: Find what was done to each letter or the whole word: shifted (+1, −1), reversed, or converted to numbers. Apply the same rule to the new word.
Q8If TABLE is coded as UBCMF, how is CHAIR coded?Show answer ▾
✔ Answer: DIBJS
Every letter moves +1: T→U, A→B, B→C, L→M, E→F. Apply to CHAIR: C→D, H→I, A→B, I→J, R→S.
Q9If CAT = 24, what is DOG?Show answer ▾
✔ Answer: 26
CAT is the sum of letter positions: C(3) + A(1) + T(20) = 24. DOG = D(4) + O(15) + G(7) = 26.
Q10If SUN is written as 19-21-14, how is MOON written?Show answer ▾
✔ Answer: 13-15-15-14
Each letter is replaced by its alphabet position: M=13, O=15, O=15, N=14.
Q11If FRIEND is coded as DNEIRF, how is MOTHER coded?Show answer ▾
✔ Answer: REHTOM
The word is simply reversed. Always test "reverse" when the coded word has exactly the same letters.
👪 Blood Relations
Trick: Work from the END of the sentence backwards, and draw a quick family tree. Never keep relations in your head.
Q12Pointing to a photo, Ram says, "She is the daughter of my grandfather's only son." Who is she to Ram?Show answer ▾
✔ Answer: His sister
Grandfather's only son = Ram's father. The daughter of Ram's father = Ram's sister.
Q13A is B's brother, B is C's sister, and C is D's father. How is A related to D?Show answer ▾
✔ Answer: Uncle
A, B, C are siblings (A male). C is D's father, so C's brother A is D's uncle.
Q14"The man in the photo is my mother's brother's son." Who is he?Show answer ▾
✔ Answer: Cousin
Mother's brother = maternal uncle. Uncle's son = cousin.
🧭 Direction Sense
Trick: Draw the path on your rough sheet with North at the top — every time. The answer is usually a right-angle triangle away.
Q15A man walks 5 km north, turns right and walks 3 km, turns right again and walks 5 km. How far and in which direction is he from the start?Show answer ▾
✔ Answer: 3 km east
North 5, east 3, then south 5 — the north and south legs cancel. He ends 3 km east of the start.
Q16A man walks 4 km east, then 3 km north. What is the shortest distance from the starting point?Show answer ▾
✔ Answer: 5 km
Pythagoras: √(4² + 3²) = √25 = 5. The 3-4-5 triangle appears constantly — recognise it on sight.
Q17Facing north, a man turns 90° clockwise, then 180° anticlockwise, then 90° clockwise. Which direction is he facing?Show answer ▾
✔ Answer: North
Net rotation = +90 − 180 + 90 = 0. He faces north again. Add the rotations instead of tracking each turn.
⚖️ Syllogisms
Trick: Trust only the statements — never real-world knowledge. Draw quick circles (Venn style): "All A are B" = A inside B; "Some A are B" = overlapping circles.
Q18All roses are flowers. All flowers need water. Conclusion: All roses need water — valid?Show answer ▾
✔ Answer: Yes
Roses sit inside flowers, flowers sit inside things-that-need-water. So roses must need water. A clean chain of "All … are …" always passes through.
Q19All pens are books. Some books are pencils. I: Some pens are pencils. II: Some pencils are books. Which follows?Show answer ▾
✔ Answer: Only II
The pencil-books overlap may not touch pens at all, so I is not certain. II simply restates "some books are pencils" in reverse, which is always valid for "some".
Q20Some cats are dogs. All dogs are birds. I: Some cats are birds. II: All birds are dogs. Which follows?Show answer ▾
✔ Answer: Only I
The cats that are dogs must also be birds, so I follows. II reverses "All dogs are birds", which is invalid — all dogs being birds doesn't make all birds dogs.
🪑 Seating & Ranking
Trick: For rows: draw blanks and fill fixed positions first. For ranking: (position from left) + (position from right) − 1 = total count.
Q21Five friends sit in a row. C is at the extreme left. A is to the immediate right of B. E is between A and D. Who sits in the middle?Show answer ▾
✔ Answer: A
Fix C at seat 1. The pair B-A and the condition "E between A and D" force the order C, B, A, E, D. The middle (3rd) seat is A.
Q22In a row of students, Ravi is 7th from the left and 5th from the right. How many students are in the row?Show answer ▾
✔ Answer: 11
Total = 7 + 5 − 1 = 11. The −1 stops you counting Ravi twice — forgetting it is the classic error.
Q23Meena ranks 4th from the top and 9th from the bottom of her class. How many students are in the class?Show answer ▾
✔ Answer: 12
Same formula: 4 + 9 − 1 = 12.
🔗 Analogy & Odd One Out
Trick: Say the relationship out loud as a sentence ("a doctor works in a hospital") and then apply that exact sentence to the options.
Q24Doctor : Hospital :: Teacher : ?Show answer ▾
✔ Answer: School
The relation is person : workplace. A teacher's workplace is a school.
Q25Book : Pages :: Ladder : ?Show answer ▾
✔ Answer: Rungs
Whole : parts. A book is made of pages; a ladder is made of rungs.
Q26Odd one out: 3, 5, 7, 9, 11Show answer ▾
✔ Answer: 9
All the others are prime numbers. 9 = 3 × 3 is composite.
🕐 Clocks & Calendars
Trick: Angle = |30×H − 5.5×M|. For calendars, count in blocks of 7 days — the day repeats every full week.
Q27What is the angle between the hands of a clock at 3:30?Show answer ▾
✔ Answer: 75°
Angle = |30×3 − 5.5×30| = |90 − 165| = 75°. The hour hand moves too — at 3:30 it's halfway between 3 and 4, which is why the answer isn't 90°.
Q28If January 1 is a Monday in a non-leap year, what day is January 29?Show answer ▾
✔ Answer: Monday
January 29 is exactly 28 days (4 full weeks) after January 1, so it lands on the same weekday.
🧠 Statements & Logic
Trick: The most common trap is the converse error: "All who X get Y" does NOT mean "everyone with Y did X."
Q29All students who work hard pass. Ram passed. Does it follow that Ram worked hard?Show answer ▾
✔ Answer: No
The rule only says hard work guarantees a pass — it doesn't say passing requires hard work. Ram may have passed some other way. This converse error is the most-tested logic trap.
Q30A is taller than B. C is shorter than B. D is taller than A. Who is the shortest?Show answer ▾
✔ Answer: C
Order: D > A > B > C. Write inequality chains left to right and the answer reads itself off.
📈 How to score high in the reasoning section
- Learn tricks by topic, then mix. Master one category at a time using the tricks above, then practise mixed sets under a timer — that's how the real test feels.
- Target 30–45 seconds per easy question. Series, analogies and odd-one-out should be near-instant so you bank time for seating puzzles.
- Always use rough paper. Family trees, direction paths, and inequality chains solved on paper are faster and more accurate than mental juggling.
- Skip and return. A stuck puzzle costs you three easy questions. Mark it, move on, come back.
- Know the traps: the −1 in ranking counts, the moving hour hand in clock angles, and the converse error in logic statements catch most freshers.
Frequently Asked Questions
What are logical reasoning questions?
Logical reasoning questions test how you think, not what you memorised — spotting patterns in series, decoding rules, tracking relationships and directions, and judging what validly follows from statements. They appear in almost every placement aptitude test, including TCS NQT, Infosys, Wipro, Accenture and Cognizant.
How do I prepare logical reasoning for placements?
Practise by topic first (series, coding-decoding, blood relations, directions, syllogisms, seating), learn the standard trick for each, then do mixed timed sets. Aim for 30–45 seconds per easy question. Consistent daily practice for 2–3 weeks beats cramming.
Which reasoning topics are most asked in placement tests?
Number and letter series, coding-decoding, blood relations, direction sense, syllogisms, and seating/ranking arrangements cover the large majority of questions in fresher-level tests like TCS NQT and Infosys aptitude rounds.
How much time should I spend per reasoning question?
Most placement tests allow roughly 45–60 seconds per question. Practise to solve easy ones in under 30 seconds so you bank time for multi-step puzzles like seating arrangements.