๐ See this first: What came in the RATIONALITY section of the official 2025 paper? (3 min read)
Topic-wise count after reading all 120 questions (12 ร 10) of the RATIONALITY section of MPESB SI Prelims 2025 (exam 16โ21 Jan 2026, 12 shifts):
| Topic | Questions out of 120 | Approx. per shift |
|---|---|---|
| Arithmetic word problems (profit-loss, time-speed, work, average, ratio) โ yes, in the Rationality section! | 39 | 3โ4 |
| Blood Relations | 19 | 1โ2 |
| Order & Ranking | 11 | 1 |
| Direction & Distance | 10 | 1 |
| Coding-Decoding | 8 | 0โ1 |
| Dictionary order / Alphabet test | 8 | 0โ1 |
| Decision Making | 8 | 0โ1 |
| Clock | 7 | 0โ1 |
| Calendar | 7 | 0โ1 |
| Number puzzles (LCM, tyres, heads-legs) | 3 | โ |
Analogy, classification, series, syllogism, Venn, puzzles, data sufficiency and figure questions (mirror, dice, paper folding) appeared in the ANALYTICAL ABILITY section in 2025 (odd-one-out, data sufficiency, floor puzzle and figure analogy came there) โ so study Topics 10โ25 too; they will help in both sections.
Official figure questions (with image options) cannot be reproduced faithfully in text here, so their method + text/SVG examples are given.
- Some official questions also had typos/wrong options (e.g. in one shift the correct ranking answer 25 was not in any option; in one "which is not a leap year" question both 700 and 1800 were non-leap). If you see this in the exam, don't panic โ choose the nearest/intended answer, or leave it (check the negative marking rule in the rulebook).
- The Hindi and English versions sometimes differ โ if in doubt, read the English version.
๐ 1. Blood Relations (12 min read ยท 18 PYQs)
Concept + Method (4 steps)
- Who is the speaker ("I/my" = the person speaking) and about whom the question asks โ underline both of these first.
- Break the sentence from the back (last): "my mother's father's daughter's son" โ my mother โ her father (my maternal grandfather) โ maternal grandfather's daughter (my mother / maternal aunt) โ her son.
- Draw a family tree: the older generation at the top, children below. Male = โก or (+), Female = โ or (โ), husband-wife = โ, brother-sister = โโ.
- Assume gender only when it is clear from the name/word (father, daughter, brother). Always give the answer as "what the first person is to the second".
Golden Shortcuts for "Only" (asked the most)
| Phrase | Meaning |
|---|---|
| "The only son of my mother / my father" (speaker is male) | = myself |
| "The only daughter of my mother" (speaker is female) | = myself |
| "The only son of my paternal grandfather" | = my father |
| "The only son of my maternal grandfather" | = my maternal uncle |
| "The only daughter of my maternal/paternal grandfather" (only mother fits in the options) | Maternal grandfather's โ mother; paternal grandfather's โ paternal aunt |
| "My father's wife" | = mother (step-mother is not assumed in the exam) |
| "The mother of my son's only daughter" | = daughter-in-law |
| "His brother's father" | = his father |
Relation Vocabulary (Hindi โ English)
| Relation | Whose | Relation | Whose |
|---|---|---|---|
| Paternal grandfather/grandmother (Dada/Dadi) | Father's father/mother | Maternal grandparents (Nana/Nani) | Mother's father/mother |
| Paternal uncle (Chacha/Tau) | Father's younger/elder brother | Maternal uncle (Mama) | Mother's brother |
| Paternal aunt (Bua) ยท her husband (Phupha) | Father's sister ยท her husband | Maternal aunt (Mausi) ยท her husband (Mausa) | Mother's sister ยท her husband |
| Nephew/Niece (Bhatija/Bhatiji) | Brother's son/daughter | Nephew/Niece (Bhanja/Bhanji) | Sister's son/daughter |
| Grandson/Granddaughter (Pota/Poti) | Son's son/daughter | Grandson/Granddaughter (Nati/Natin or Navasa/Navasi) | Daughter's son/daughter |
| Brother/Sister-in-law (Sala/Sali) | Wife's brother/sister | Brother-in-law (Devar/Jeth) ยท Sister-in-law (Nanad) | Husband's younger/elder brother ยท husband's sister |
| Brother-in-law (Jija) | Sister's husband | Sister-in-law (Bhabhi) | Brother's wife |
| Father/Mother-in-law (Sasur/Saas) | Husband's/wife's father/mother | Son-in-law (Damad) ยท Daughter-in-law (Bahu) | Daughter's husband ยท son's wife |
| Cousin = child of a paternal uncle/maternal uncle/paternal aunt/maternal aunt (Chachera, Mamera, Phuphera, Mausera brother-sister). English "Uncle" = both Chacha and Mama; "Aunt" = Bua, Mausi, Chachi, Mami. | |||
Coded Relations (A + B, A ร B type)
The meaning of the symbols is given. Decode one pair at a time from left to right, then connect the first and the last person. Note the gender from every symbol as you go.
Step 2: Brother-in-law = son of the woman's brother โ the woman's brother = the brother-in-law's father = my father-in-law.
Step 3: Woman = father-in-law's sister = wife's paternal aunt (Bua Saas).
โด A is D's father. (D's gender is not known โ so saying "D is A's son" would be wrong.)
- "Only son" + male speaker = he himself. (The Girish/Abhi PYQs were based on this.)
- A useless person (distractor) is also given โ e.g. in the Chotu PYQ, "Fatu" had no role.
- If gender is not known, do not choose a "son/daughter" option; if the options have "cannot be determined", consider that.
- Reverse question: "relation of A to B" โ "relation of B to A". Re-read the direction of the question.
- In some PYQs, strictly two possibilities arise (e.g. "grandfather's granddaughter" = daughter as well as niece) โ the answer is the only one of these that is in the options.
Chotu and Motu are brothers โ Chota is the father of both โ Gotu (Chota's father) = Chotu's grandfather. Fatu is a distractor.
Kashyap = Arvind's son; Harish = son of Arvind's brother Sanhit โ paternal cousin brother (cousin).
Grandfather's only son = the woman's father. The man's brother's father = the man's father. Both have the same father โ the woman is his sister.
Grandfather's only daughter = Geeta's mother (this is what fits the options). Mother's only son = Geeta's brother โ Geeta is his sister.
My daughter's uncle = my brother. The woman's son = Raghu's brother โ the woman is Raghu's mother.
Surya's only son is Kiran โ Surya's granddaughter (son's daughter) = Kiran's daughter. Only this is possible in the options.
P ร Q โ P is Q's daughter. Q รท R โ Q is R's father. P and R are both Q's children, P is female โ P is R's sister.
The only daughter of Monika's father = Monika herself โ Monika = Pahul's mother โ Monika's husband = Pahul's father.
Mother's only son = Girish himself โ the boy is Girish's son โ Girish is his father.
Mother of son's daughter = son's wife = daughter-in-law (Bahu).
Father's wife = mother โ mother's daughter = Harsh's sister โ Harsh is her brother.
R is S's daughter and D is R's brother โ D is S's son. S's gender is not given, but in the options only "son and father" (D = son) fits.
The only daughter of my mother = the woman herself โ she is the man's mother.
Father's wife = mother โ mother's sister = maternal aunt.
Intended chain: Y = Z's mother โ Z's maternal grandmother = Y's mother = X's mother too โ W = father of X's mother โ X is W's granddaughter (daughter's daughter, Natin). In the options, English "Granddaughter" covers both Poti (son's daughter) and Natin (daughter's daughter).
Father of Vinay's sister = Vinay's father = Vidya's husband.
Father's only son = Abhi himself โ his only daughter = Abhi's daughter.
๐ 2. Order & Ranking (8 min read ยท 10 PYQs)
Formulas (everything is built from these)
| Situation | Formula |
|---|---|
| One person: L from the left, R from the right | Total = L + R โ 1 |
| Total N, k from the top โ from the bottom? | N โ k + 1 |
| Two persons, counted from opposite ends, x people between them, no overlap | Total = L + R + x |
| Two persons, positions overlap/cross | Total = L + R โ x โ 2 |
| A and B change places (interchange) | A's new position = B's old position (from the same end) |
| Between two people (positions p < q from the same end) | In between = q โ p โ 1 |
- "Other than A and B" / "other than" โ subtract 2 from the total.
- Adding new students at the bottom of the list does not change the rank from the top (the Luno PYQ).
- "4 boys in between" means the difference in positions is 5.
- If both orders (A first or B first) are possible, make both cases โ pick the one in the options; if "minimum" is asked, take the smaller one.
No overlap: 14 + 4 + 7 = 25. (Overlap case = 9 + 7 โ 1 = 15, not in the options.)
Total = 18 + 10 โ 1 = 27; other than A, B = 25. (In 18 Jan Shift 1 the same question came with wrong options โ 13/12/7/3.)
C = 12th from the front. B = 12 ยฑ 8 = 4 or 20. A = B ยฑ 5 โ if B = 4 then A = 9 โ Total = 9 + 13 = 22. (With B = 20, A = 15/25 โ Total 28/38, more.) Minimum = 22.
G = 16 + 11 = 27th from the left. G is third to the right of V โ V = 24 (from the left). V is 18 from the right โ Total = 24 + 18 โ 1 = 41.
๐ 3. Direction & Distance (10 min read ยท 10 PYQs)
Method: Coordinate (x, y) method โ never goes wrong
- Start = (0, 0). East = +x, West = โx, North = +y, South = โy.
- Add or subtract every walk in x or y. At the end you get (x, y).
- Distance = โ(xยฒ + yยฒ). Direction: x+, y+ โ NE; xโ, y+ โ NW; x+, yโ โ SE; xโ, yโ โ SW; if only x or only y, then a straight direction.
- Turning right = clockwise 90ยฐ; left = anticlockwise 90ยฐ. N โ right = E, E โ right = S, S โ right = W, W โ right = N.
Shadow Rules
| Time | Sun | Shadow |
|---|---|---|
| Morning (after sunrise) | East | West |
| Evening (before sunset) | West | East |
Then see whether the shadow is to the person's right/left/front/back. Remember: facing North โ right = East, left = West. Facing South โ right = West, left = East. Facing East โ right = South. Facing West โ right = North.
"In which direction is A from B?"
Take B as the origin (0,0) and see A's position. Don't reverse it โ "In which direction is Q from R" = where Q is when seen from R.
Questions where directions change (SE โ N type)
From the first pair, find how many degrees and in which direction it has turned (N=0ยฐ, NE=45ยฐ, E=90ยฐ, SE=135ยฐ, S=180ยฐ, SW=225ยฐ, W=270ยฐ, NW=315ยฐ). Apply the same turn to the other direction.
- "Walking towards the sun" in the morning = towards East; in the evening = towards West.
- Two people standing face to face: if one faces North, the other faces South.
- Whether "how far" is asked or "how much did he walk in total" โ the two are different (total walk = sum of all distances).
- If the options do not have the direction but the answer comes out SW/NE, look at "none of these".
N20 โ (0,20); right = E30 โ (30,20); right = S35 โ (30,โ15); left = E15 โ (45,โ15); left = N15 โ (45, 0). โ 45 m East.
๐ 4. Clock (10 min read ยท 7 PYQs)
Basic Facts
| Fact | Value |
|---|---|
| Speed of the minute hand | 6ยฐ per minute (360ยฐ / 60 min) |
| Speed of the hour hand | 0.5ยฐ per minute = 30ยฐ per hour |
| Relative difference between the two | 5.5ยฐ per minute |
| Between two numbers (e.g. 12 and 1) | 30ยฐ (5 minute spaces) |
Hands coincide (0ยฐ) between H and H+1: M = 60H/11 โ e.g. between 4 and 5 at 240/11 = 219โ11 minutes.
Hands opposite (180ยฐ): find M from 5.5M = 30H ยฑ 180.
Right angle (90ยฐ): find M from 5.5M = 30H ยฑ 90 (twice every hour โ with a few exceptions).
| How many times? | In 12 hours | In 24 hours (1 day) |
|---|---|---|
| Hands coincide | 11 | 22 |
| Hands opposite in a line (180ยฐ) | 11 | 22 |
| Hands in a straight line (0ยฐ or 180ยฐ) | 22 | 44 |
| Right angle (90ยฐ) | 22 | 44 |
In a correct clock, the hands meet every 655โ11 minutes. If in some clock they meet every 65 minutes, that clock is running fast.
How much has the hour hand turned?
Time difference (minutes) ร 0.5ยฐ. E.g. 12:00 to 7:10 = 430 min ร 0.5 = 215ยฐ.
Fast/Slow Clock (Gain/Loss) Method
- Find how much the clock is behind/ahead at the first time and how much ahead/behind at the second time โ the total change (if behind โ ahead, add them).
- Find the total hours between the two times.
- The correct time will be when the initial difference is wiped out: time = (total hours ร initial difference) รท total change.
- At 8:30 the hour hand is not on 8, but between 8 and 9 โ so the answer is 75ยฐ, not 60ยฐ.
- For "how many degrees has the hour hand turned", use only 30ยฐ per hour; not the formula |30H โ 5.5M|.
- Clock questions with mirror/water images โ see Topic 23.
Monday 12 noon to next Monday 2 pm = 7ร24 + 2 = 170 hours. Total change = 2 + 4.8 = 6.8 minutes. To correct 2 minutes = 170 ร 2/6.8 = 50 hours โ Monday noon + 50 h = Wednesday 2 pm.
Coinciding between 8โ9: M = 480/11 = 437โ11 โ 8:437โ11. Between 2โ3 at 180ยฐ: 5.5M = 60 + 180 โ M = 437โ11 โ 2:437โ11. Difference = exactly 6 hours.
๐ 5. Calendar (10 min read ยท 6 PYQs)
Odd Days โ the complete concept
The remainder left after dividing by 7 = odd days. The same weekday returns after every 7 days.
| Period | Odd days |
|---|---|
| Ordinary year (365 days) | 1 |
| Leap year (366 days) | 2 |
| 100 years | 5 |
| 200 years | 3 |
| 300 years | 1 |
| 400 years (and 800, 1200, 1600, 2000) | 0 |
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Odd days | 3 | 0 (leap: 1) | 3 | 2 | 3 | 2 | 3 | 3 | 2 | 3 | 2 | 3 |
Day code: 0 = Sunday, 1 = Monday, 2 = Tuesday, 3 = Wednesday, 4 = Thursday, 5 = Friday, 6 = Saturday.
โ Leap: 1600, 2000, 2400, 800, 1200, 2024 ยท โ Not leap: 700, 1800, 1900, 2100, 2026
On the same date next year: weekday moves +1; if 29 Feb comes in between, +2.
On the same date last year: weekday โ1; if 29 Feb is in between, โ2.
Weekday of any date (Method)
- Odd days of the previous complete years: centuries (multiple of 400 = 0) + remaining years (ordinary ร 1 + leap ร 2).
- Odd days of the complete months of that year + the given date.
- Total รท 7 โ remainder = day code.
In 1947: Jan 3 + Feb 0 + Mar 3 + Apr 2 + May 3 + Jun 2 + Jul 3 + 15 (Aug) = 31 โ remainder 3.
Total = 2 + 3 = 5 โ Friday โ
Other important Facts
- A weekday 53 times: an ordinary year has 52 weeks + 1 day โ probability of it coming 53 times is 1/7; a leap year has 52 weeks + 2 days โ 2/7.
- Calendar repeat: a leap year's calendar repeats after 28 years (e.g. 2024 โ 2052); the year after a leap year after 6 years (2025 โ 2031); the other two years after 11 years (2026 โ 2037, 2023 โ 2034). (This can change if a non-leap century year comes in between.)
- The last day of a century (31 Dec 1900/2000...) can only be Monday, Wednesday, Friday or Sunday โ never Tuesday, Thursday or Saturday.
- "If yesterday were tomorrow, today would be Friday" type: real today = T. Treat yesterday (T โ 1) as "tomorrow" โ then "today" = T โ 2 = Friday โ T = Sunday.
- 1800, 1900, 700 are not leap years (not divisible by 400). 2000, 1200, 800 are leap years.
- 20 March 1991 โ 20 March 1992: 29 Feb 1992 comes in between โ +2 (not just +1).
- 8 Feb 2004 โ 8 Feb 2005: 29 Feb 2004 comes in between โ โ2.
Up to 2001: 2000 years โ 0; 2001 โ 1. 2002: Jan 3 + Feb 0 + Mar 3 + Apr 2 + May 3 + 10 = 21 โ 0. Total = 1 โ Monday.
๐ 6. Coding-Decoding (10 min read ยท 8 PYQs)
Alphabet Positions (worth memorising)
Opposite letters (sum = 27): AโZ, BโY, CโX, DโW, EโV, FโU, GโT, HโS, IโR, JโQ, KโP, LโO, MโN.
To remember: AZad, BoY, DeW, GT road, HS (High School), IR (Indian Railway), KP, LOve, MN.
Main types of Coding
| Type | How to identify | Example |
|---|---|---|
| Letter shift (+n / โn) | Every letter moves equally forward/backward | NIGHT โ OJHIU (+1) |
| Increasing shift | +1, +2, +3... or โ1, โ2, โ3... | DELHI โ CCIDD (โ1, โ2, โ3, โ4, โ5) |
| Opposite letter | Each letter's pair (sum 27) | COLD โ XLOW |
| Reverse / writing backwards | Word from the back | PENCIL โ LICNEP |
| Letter โ number | Position or a digit for some letter | EXAM โ 5X1M (E = 5, A = 1, the rest as they are) |
| Digit substitution | One digit for each letter | DELHI = 45189 โ D4 E5 L1 H8 I9 |
| Sum coding | Sum of positions | CAT = 3 + 1 + 20 = 24 |
| Shift + swap (mixed) | After the shift, some letters change places | FRIEND โ EQHDCM (โ1, then the last two letters swapped with each other) |
| Sentence / word coding | Common word in two sentences = common code | Example below |
- Don't decide the pattern from only the first 2 letters โ check the whole word (in the FRIEND PYQ the last two letters were swapped).
- After Z, go back to A (wrap around): Y + 3 = B.
- Options differ by one letter at a time โ don't choose by matching only the first and last letters.
FRIEND โ1 = E Q H D M C, then swap the last two letters โ EQHDCM โ. FAMILY โ1 = E Z L H K X โ swap โ EZLHXK.
๐ 7. Dictionary Order & Alphabet Test (7 min read ยท 8 PYQs)
Dictionary Order Rules
- Compare the first letter; if equal, the second, then the third... wherever the first difference comes, that decides.
- If one word is the starting part (prefix) of another, the shorter word comes first: Gad < Gadfly; Dwell < Dwelling < Dwellings.
- Not the length of letters but the order matters: Type (type) < Typhoon (typh) < Typical (typi) < Tyrant (tyr).
Order: Climax, Cling, Clinic, Clinker, Clip โ Clinic comes after Cling.
Alphabet Test Formulas
| Question | Formula |
|---|---|
| k-th letter from the left | Position k |
| k-th letter from the right | Position 27 โ k |
| m-th to the right of the k-th letter from the left | k + m |
| m-th to the left of the k-th letter from the right | 27 โ k โ m |
| Letter exactly midway between two letters (positions p, q) | (p + q) รท 2 |
- "Comes after" = only the immediately next word (from the options), not the very last one.
- A plural (Dwellings) comes right after its singular (Dwelling).
๐ 8. Decision Making & Course of Action (7 min read ยท 7 + 2 PYQs)
6 rules for choosing the right option (think like a Police officer)
- Safe โ safety of yourself and others first (walking alone on an unsafe route at night โ, a safe cab โ).
- Legal/Ethical โ breaking rules, bribery, lying, making a photo viral โ.
- Direct effect on the problem โ the measure that reduces the problem directly and quickly (malnutrition โ free meals and cheap ration).
- Talk / consult โ mediation in a conflict, talk to the family in a family decision, ask the manager about priority when there are two urgent tasks.
- Extreme option โ โ hunger strike, refusing/resigning immediately, selling the vehicle, leaving without informing.
- Ignoring โ โ "it will get fixed on its own" is almost never right.
๐ 9. Arithmetic Questions of the Rationality Section (Profit-Loss, Speed, Work, Average...) (15 min read ยท 39 PYQs)
In 2025, 39 of the 120 Rationality questions were direct arithmetic. The full concept is in the Mathematics notes; here only the essential formulas + all official questions with solutions.
Formula Recap (at a glance)
| Topic | Formula / Trick |
|---|---|
| Profit / Loss | SP = CP ร (100 ยฑ %)/100 ยท CP = SP ร 100/(100 ยฑ %) ยท Profit% = (Profit/CP) ร 100 |
| SPs given for x% profit and x% loss (equal %) | CP = average of the two SPs: (SPโ + SPโ)/2 |
| Price rises by r%, keep expenditure the same | Reduce consumption = r/(100 + r) ร 100 % |
| km/h โ m/s | ร 5/18 (km/h โ m/s) ยท ร 18/5 (m/s โ km/h) |
| Equal distance, two speeds x, y | Average speed = 2xy/(x + y) |
| Moving towards each other | Time = distance รท (speedโ + speedโ) |
| Stoppage per hour | (speed without stoppage โ speed with stoppage)/speed without stoppage ร 60 minutes |
| Ratio of speeds a : b : c | Ratio of times = 1/a : 1/b : 1/c |
| Work | 1 day's work = 1/days; together = add; MโDโ = MโDโ |
| Partnership | Ratio of profit = capital ร time |
| Average | Total = average ร number |
| Mixture profit | Find total CP and total SP, then profit% |
- Some official options had typos (e.g. height "166 m" = 166 cm; "1.57" = 157%). Identify the correct value and choose the option.
- If "approximately" is written, do the full calculation and take the nearest option.
- "Loss equal to x" type: SP = CP of (total โ x) items.
Source of all Q1โQ39: MPESB SI Prelims 2025, Rationality section (date and shift given on each question).
๐ 10. Syllogism (10 min read)
How to draw it with Venn diagrams
Definite Rules
| Statement | Definitely true | Not definite (only a possibility) |
|---|---|---|
| All A are B | Some A are B ยท Some B are A | All B are A |
| Some A are B | Some B are A | All A are B ยท All B are A |
| No A is B | No B is A ยท Some A are not B ยท Some B are not A | โ |
| Some A are not B | (it has no conversion) | โ |
Shortcut for combining two Statements (remove the common middle term)
| Statement 1 (AโB) | Statement 2 (BโC) | Conclusion (AโC) |
|---|---|---|
| All | All | All A are C |
| All | No | No A is C |
| Some | All | Some A are C |
| Some | No | Some A are not C |
| All | Some | No definite conclusion |
| Some | Some | No definite conclusion |
| No | All | Some C are not A (not about A, about C) |
โข A possibility conclusion is true when it does not break any definite fact.
โข Either-or: when neither of two conclusions is definite, but they form a "some" + "no" pair (or "all" + "some not") on the same subject-predicate โ "Either I or II".
โข Don't apply real-world knowledge โ if "All dogs fly" is given, accept exactly that.
- "All A are B" does not give "All B are A".
- "Some" means "at least one" โ it can also be "all".
- If the subject of the conclusion is reversed, check it only after applying the conversion rule.
๐ 11. Statement-Conclusion, Statement-Assumption & Cause-Effect (Statement-based Reasoning) (7 min read)
| Type | What is asked | Rule for accepting it |
|---|---|---|
| Conclusion | What definitely follows from the statement | It must come directly from the facts of the statement only; not your own opinion/outside information. Extreme conclusions with "only", "always", "all" are often โ. |
| Assumption | What the speaker has already taken for granted (not written) | If, without that belief, the statement would become meaningless โ then it is an assumption โ. (Negation test) |
| Course of Action | What step should be taken | Practical + reduces the problem + not extreme (Topic 8). |
| Argument (Strong/Weak) | Whether the argument is strong or weak | Linked to the main issue, fact-based = strong; emotional/vague/mere example = weak. |
| CauseโEffect | Of two events, which is the cause and which the effect | What happened first and what caused the second; both can also be effects of some third cause, or independent. |
- Even a conclusion that seems true is โ if it does not follow from the statement.
- In cause-effect, the order of time alone is not enough โ a direct link is needed.
๐ 12. Venn Diagrams (6 min read)
Identifying which figure best shows the relationship between three (or two) classes.
| Words | Relationship | Figure |
|---|---|---|
| Rupee, currency, money | One inside another (rupee โ currency โ money) | (a) |
| Man, woman, human | Man and woman separate, both inside human | (b) |
| Teacher, woman, mother | Mother โ woman; teacher overlaps both | (c) |
| Doctor, lawyer, man | Doctor and lawyer separate; both overlap with man (some doctors are men) | Two separate circles, both cutting a third |
| Bird, crow, cow | Crow โ bird; cow separate | One inside another + one separate |
Venn with numbers (two sets)
๐ 13. Analogy (6 min read)
A : B :: C : ? โ the relationship in the first pair is the same in the second pair. First say the relationship in a short sentence ("a doctor works in a hospital"), then apply the same sentence to C.
| Type of relationship | Example |
|---|---|
| Place of work | Doctor : Hospital :: Teacher : School |
| Tool : work | Pen : Write :: Knife : Cut |
| Creature : home | Bird : Nest :: Lion : Den ยท Bee : Hive |
| Young one | Cow : Calf :: Dog : Puppy |
| Measuring instrument | Temperature : Thermometer :: Earthquake : Seismograph |
| Antonym / synonym | Hot : Cold :: High : Low |
| Country : capital / state : capital | India : New Delhi :: Madhya Pradesh : Bhopal |
| Number (square, cube, nยฒ ยฑ 1) | 3 : 27 :: 5 : 125 (cube) ยท 6 : 35 :: 8 : 63 (nยฒ โ 1) |
| Letters (shift) | ACE : BDF :: GIK : HJL (+1) |
๐ 14. Classification โ Odd One Out (5 min read ยท 2 PYQs)
Three of the four share some common property; the one that is different is the answer. Check-list: category (fruit/vegetable, planet/satellite), prime/composite, even/odd, square/cube, divisibility by some number, gap between letters, vowel/consonant.
๐ 15. Series (Number, Letter & Alphanumeric Series) (8 min read)
Number Series โ Order of checking
- Find the difference โ constant (AP)? increasing? difference of differences?
- Multiplication/division (ร2, ร3) or ร k + m (ร2 + 1).
- Near squares/cubes: nยฒ, nยฒ ยฑ 1, nยณ, nยณ ยฑ 1, n(n + 1).
- Prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37... (1 is not prime).
- Alternate: 1st, 3rd, 5th form one series; 2nd, 4th, 6th another.
| Pattern | Series | Next |
|---|---|---|
| Differences 2, 4, 6, 8... | 4, 6, 10, 16, 24 | 34 |
| n(n + 1) | 2, 6, 12, 20, 30 | 42 |
| nยฒ + 1 | 2, 5, 10, 17, 26 | 37 |
| nยณ โ 1 | 0, 7, 26, 63, 124 | 215 |
| ร2 + 1 | 3, 7, 15, 31, 63 | 127 |
| ร2 + 1, ร2 + 2, ร2 + 3... | 3, 7, 16, 35, 74 | 153 |
| Squares of prime numbers | 4, 9, 25, 49, 121 | 169 |
Letter / Alphanumeric Series
Convert letters into numbers (A = 1...) and apply the same number rules. If there are groups, look at the first letter, second letter of each group separately.
- In "wrong term" questions, first confirm the pattern, then pick the term that does not match it.
- In letter series, after Z comes A again (wrap).
๐ 16. Missing Number (Matrix/Figure) (5 min read)
Look for the pattern in rows; if not found, in columns. Common patterns: sum, product, aยฒ + bยฒ, (a + b) ร 2, a ร b โ c, middle number = sum/product of the rest.
๐ 17. Mathematical Operations, Symbol Substitution & Inequality (6 min read)
Symbol Substitution โ Method
- First replace the given symbols with the real symbols and rewrite the whole expression.
- Then BODMAS: brackets โ division (รท) โ multiplication (ร) โ addition (+) โ subtraction (โ). (Division and multiplication in left-to-right order.)
Inequality โ Rules
- A > B โฅ C = D โ comparing A and D: if there is no opposite sign (< or โค) on the way, they connect โ A > D.
- If two signs point in opposite directions (> and <) โ no definite relation.
- If even one sign in the chain is strict (>), the result is strict (>); if all are โฅ/=, then โฅ.
- "Either A โฅ B or A < B" type โ when neither is definite and together they cover all possibilities.
๐ 18. Seating Arrangement โ Linear & Circular (8 min read)
Left-Right Rules
| Situation | Right | Left |
|---|---|---|
| Row, facing North (you are also looking the same way) | Your right | Your left |
| Row, facing South (towards you) | Your left | Your right |
| Round table, facing the centre | Anticlockwise | Clockwise |
| Round table, facing outward | Clockwise | Anticlockwise |
- "Immediate right" โ "right (anywhere on the right side)".
- At a round table, the right of a person facing "the centre" = anticlockwise โ this is where most mistakes happen.
๐ 19. Puzzles โ Floor, Table & Number Puzzles (8 min read ยท 3 PYQs)
Floor Puzzle Method
Write the floors from 1 (lowest/ground) upwards. "Immediately above/below" = consecutive floors; "x people in between" = floor difference x + 1. Definite information first, then pairs, then cases.
Table (Grid) Method โ "who likes what"
Number Puzzles โ Tricks
- Remainder 1 less than every divisor (9 by 10, 8 by 9 ... 1 by 2): number = LCM โ 1.
- Heads-legs: assume all are 2-legged โ extra legs รท 2 = number of 4-legged ones.
- Spare tyre: total tyre-distance รท tyres running at the same time.
๐ 20. Data Sufficiency (5 min read ยท 1 PYQ)
You do not have to find the answer, only decide whether the given information is enough or not. Check I alone first, then II alone, then both together.
| Option (usual order) | When |
|---|---|
| Only I is sufficient | I gives a definite answer, II does not |
| Only II is sufficient | II gives a definite answer, I does not |
| Either I or II | Either one alone is enough |
| I and II together | Neither alone, but together enough |
| Neither I nor II | Not enough even together |
๐ 21. Input-Output (Machine Input) โ Basics (4 min read)
An input line changes by some rule at every step. Compare the steps carefully to identify the rule โ often: bringing the largest/smallest number or the first word in dictionary order to the left (or right) end one by one.
๐ 22. Dice & Cube (8 min read)
Dice Rules
- Standard dice: sum of opposite faces is 7 โ (1, 6), (2, 5), (3, 4).
- Faces seen in the same view are adjacent to each other, never opposite.
- One face common (in two views): starting from the common face, write the faces of both views clockwise; faces that come in the same position are opposite to each other.
- Two faces common: the remaining third faces are opposite to each other.
- If the four neighbours of a face are known โ the remaining sixth face is its opposite.
Open dice (Net) โ opposite faces
Painted Cube (cut into n ร n ร n, all outer faces painted)
| Type | Formula | n = 3 | n = 4 |
|---|---|---|---|
| Total small cubes | nยณ | 27 | 64 |
| 3 faces painted (corners) | 8 (always) | 8 | 8 |
| 2 faces painted (edges) | 12(n โ 2) | 12 | 24 |
| 1 face painted | 6(n โ 2)ยฒ | 6 | 24 |
| No face painted (inside) | (n โ 2)ยณ | 1 | 8 |
Minimum cuts to get nยณ pieces = 3(n โ 1) (e.g. 6 cuts for 27 pieces).
๐ 23. Mirror & Water Image (7 min read)
| Mirror image (vertical mirror) | Water image (water surface) | |
|---|---|---|
| What gets reversed | Left โ right (lateral inversion) | Top โ bottom |
| Order of the letters of a word | Gets reversed + every letter flips | Order stays the same, every letter flips upside down |
| Example: POLICE | POLICE | POLICE |
| Capital letters that do not change | A H I M O T U V W X Y | B C D E H I K O X |
โข 4:20 โ 11:60 โ 4:20 = 7:40 ยท 3:15 โ 8:45 ยท 12:35 โ 23:60 โ 12:35 = 11:25
Water image of a clock (exam shortcut): subtract the given time from 18:30 (if the minutes are more than 30, from 17:90). This is the rule given in exam books.
- In a mirror image, flipping only the letters is not enough โ the order is also reversed (right โ left).
- In a mirror question, see on which side the mirror is placed (right/below) โ a mirror placed below = like a water image.
- Official figure questions come with image options; there, move every part to the opposite side at an equal distance from the mirror line.
๐ 24. Paper Folding / Cutting (5 min read)
โข Number of holes = holes punched ร 2number of folds (if the hole goes through all layers and is not on the fold line). 1 fold โ ร2, 2 folds โ ร4, 3 folds โ ร8.
โข A half cut made on the fold line (e.g. a semicircle) becomes one full shape (a full circle) on opening.
โข Order of opening = reverse of the order of folding (open the last fold first).
๐ 25. Embedded Figures & Counting Figures (7 min read)
Embedded Figure โ Method
- Identify some special part of the given small figure (a sharp corner, a slanting line, a curve).
- Look for the same part in the larger figures (options) in the same size and the same direction โ usually rotating is not allowed.
- Then match the remaining lines; if even one line is missing, the option is โ.
Counting Figures โ Formulas
| Figure | Formula | Example |
|---|---|---|
| Triangle with lines from the vertex to the base, base in n parts | n(n + 1)/2 | n = 3 โ 6; n = 4 โ 10 |
| The above figure + lines parallel to the base (total m including the base) | m ร n(n + 1)/2 | n = 3, m = 2 โ 12 |
| Square + both diagonals | 8 triangles | โ |
| Squares in an n ร n grid | 1ยฒ + 2ยฒ + ... + nยฒ | 3ร3 โ 14; 4ร4 โ 30 |
| Rectangles in an m ร n grid (including squares) | [m(m + 1)/2] ร [n(n + 1)/2] | 2ร2 โ 3 ร 3 = 9; 2ร3 โ 3 ร 6 = 18 |
โ Last-week Revision Checklist
- Blood relation: "only son/daughter" = oneself; family tree + gender.
- Ranking: L + R โ 1; interchange = the other person's old position; "other than" โ โ2.
- Direction: (x, y) method; morning shadow West, evening East; North face โ right is East.
- Clock: |30H โ 5.5M|; hour hand 0.5ยฐ/min; meeting M = 60H/11; gain/loss ratio.
- Calendar: year +1 (+2 if 29 Feb is in between); 1800/1900 not leap; 53 days โ 1/7 or 2/7.
- Coding: check the pattern on the whole word; opposite letters sum to 27.
- Dictionary: letter by letter; the shorter prefix word comes first.
- Decision: safe + legal + direct + consult; extreme/ignore โ.
- Arithmetic: profit-loss, time-speed, work โ 3โ4 questions in every shift of Rationality.