Analogy & Classification

Analogy means SIMILARITY or correspondence. In an analogy question, the relationship between the first pair must be applied to the second pair. Format: A : B :: C : ? You must find how B relates to A, then apply the SAME logic to C.

Key rule: Always check the relationship FIRST (square, cube, multiply, add, prime, etc.), then confirm direction. Memory aid: 'Same Maths Both Sides.' If 2:8 means 2-cubed=8, then 3:? must be 3-cubed=27.

Common number relations: square (4:16), cube (3:27), double (5:10), +consecutive, multiply, prime numbers, and digit-sum. Always test the simplest operation first before trying complex ones.

For letter analogies, memorize letter positions both forward and backward (EJOTY trick: E=5, J=10, O=15, T=20, Y=25). Reverse positions: A=26, B=25... (use 27-position rule: position from end = 27 minus forward position).

Common patterns: (1) Equal gaps — AC:EG means +2 each, then jump. (2) Opposite letters — A↔Z, B↔Y (sum of positions = 27). (3) Skip letters — A,C,E (skip one). (4) Reverse order.

Memory aid: 'AZ-BY-CX' opposite pairs always add to 27. Write A=1 to Z=26 mentally. Shortcut: to find opposite of any letter, do 27 minus its number. Opposite of D(4) = 27-4 = 23 = W.

Q: 7 : 50 :: 9 : ?
Step 1: Find relation. 7×7=49, 49+1=50. So pattern is (n² + 1).
Step 2: Apply to 9. 9×9=81, 81+1=82. Answer = 82.

Q: 6 : 42 :: 8 : ?
Relation: 6×7=42, i.e. n×(n+1). Apply: 8×9=72. Answer = 72.

Tip: When the result is slightly above a perfect square, test n²±1 or n²±2. When result is product of two consecutive numbers, test n(n+1). Always verify your rule on the FIRST pair completely before applying it — a rule that fits the first pair is the correct one.

Word analogies test how two words are connected. Identify the EXACT relationship, then apply it. Common types:

1. Synonyms: Happy : Joyful
2. Antonyms: Hot : Cold
3. Worker–Tool: Carpenter : Saw
4. Worker–Product: Author : Book
5. Animal–Young one: Cow : Calf
6. Cause–Effect: Disease : Death
7. Part–Whole: Wheel : Car
8. Object–Function: Pen : Write
9. Container–Contents: Glass : Water.

Memory aid: 'STWAP' — Synonym, Tool, Worker-product, Animal-young, Part-whole. Make a clear sentence: 'A carpenter uses a saw' → 'A tailor uses a ___ (needle).'

Frequently asked animal–young one analogies (memorize these):
• Cow → Calf
• Dog → Puppy
• Cat → Kitten
• Horse → Foal/Colt
• Sheep → Lamb
• Goat → Kid
• Hen → Chick
• Lion → Cub
• Bear → Cub
• Deer → Fawn
• Frog → Tadpole
• Butterfly → Caterpillar (larva)
• Cock/Hen → Chick.

Also dwelling places: Dog→Kennel, Horse→Stable, Lion→Den, Bee→Hive, Bird→Nest, Cow→Shed/Byre, Pig→Sty, Hen→Coop. And animal sounds: Lion→Roar, Dog→Bark, Cat→Mew, Horse→Neigh, Snake→Hiss. These three categories (young one, home, sound) appear in nearly every RPF reasoning set.

Q: Doctor : Hospital :: Teacher : ?
Relation: A doctor works in a hospital → workplace relationship. A teacher works in a school. Answer = School.

Q: Bird : Nest :: Bee : ?
Relation: A bird lives in a nest → dwelling. A bee lives in a hive. Answer = Hive.

Q: Hunger : Food :: Thirst : ?
Relation: Hunger is satisfied by food → need : satisfier. Thirst is satisfied by water. Answer = Water.

Tip: Frame a SHORT sentence linking the first pair, then plug in the third word. If the sentence still makes sense, your option is correct. The most precise relationship wins over a loosely-fitting one.

Classification (Odd-One-Out) asks you to find the item that does NOT belong with the rest. Three or four items share a common property; one breaks the pattern.

Steps: (1) Look for the common feature among MOST items — category, shape, number property, alphabet pattern. (2) The odd one lacks that feature.

Memory aid: 'Three same, One different.' Always assume the majority defines the rule. Categories tested: living/non-living, fruits/vegetables, perfect squares vs non-squares, primes vs composites, even vs odd, metals vs non-metals, and letter-gap patterns. Tip: If unsure, group items by category — the loner is your answer.

When classifying NUMBERS, test these properties in order:

1. Prime vs composite (2,3,5,7,11... are prime).
2. Perfect square (1,4,9,16,25,36,49,64,81,100).
3. Perfect cube (1,8,27,64,125).
4. Even vs odd.
5. Divisibility (all multiples of 3, 5, etc.).
6. Digit-sum patterns.

Memory aid: 'P-S-C-E-D' (Prime, Square, Cube, Even, Divisible). Example: 4, 9, 16, 17 → 4,9,16 are perfect squares but 17 is prime → 17 is odd one. Always test the simplest property first. If only ONE number fails a property that all others share, that is your answer.

Q: Choose the odd one: Apple, Mango, Carrot, Banana.
Reasoning: Apple, Mango, Banana are fruits; Carrot is a vegetable (root). Odd one = Carrot.

Q: 8, 27, 64, 100.
Reasoning: 8 = 2³, 27 = 3³, 64 = 4³ are perfect cubes; 100 is a perfect square but not a cube. Odd one = 100.

Q: Letters — DF, GI, JL, MN.
Reasoning: DF (gap 1: D_F), GI (G_I), JL (J_L) all skip one letter; MN has NO gap (consecutive). Odd one = MN.

Tip: For letters, write down the position gap. Three matching gaps + one different = the different one is the answer.

Some questions give a word pair and ask which OPTION PAIR has the same relationship. Method: (1) Identify the exact relationship in the given pair. (2) Test each option pair against that EXACT relationship. (3) Reject options that match loosely but in the WRONG direction.

Direction matters! If the pair is 'Country : Capital', then 'India : Delhi' is correct but 'Delhi : India' is reversed (wrong). Memory aid: 'Same Relation, Same Order.'

Watch for trap options that are related but by a DIFFERENT relationship (e.g., synonym instead of antonym). Always state the relationship in words first — it makes elimination fast and reliable.

RPF analogies often need basic General Knowledge. Memorize:
• Country : Capital → India : New Delhi, Japan : Tokyo, France : Paris.
• Country : Currency → India : Rupee, USA : Dollar, Japan : Yen, UK : Pound.
• State : Capital → Maharashtra : Mumbai, Bihar : Patna.
• Instrument : Measures → Thermometer : Temperature, Barometer : Pressure, Speedometer : Speed, Seismograph : Earthquake.
• Author : Work, Inventor : Invention.

Memory aid for instruments: 'Thermo-Temp, Baro-Pressure, Speedo-Speed, Seismo-Quake.' These instrument analogies are extremely common — knowing what each device measures secures easy marks.

Q: Find the pair like 'Thermometer : Temperature'.
Relation: instrument : quantity it measures.
Options: (a) Clock : Wall (b) Barometer : Pressure (c) Pen : Ink (d) Car : Road.
Only (b) Barometer : Pressure is instrument : measured quantity. Answer = Barometer : Pressure.

Q: 'India : Rupee' is like?
Relation: country : currency. Japan : Yen fits. (Tokyo would be capital — wrong relation.)

Tip: When options seem close, recheck the SPECIFIC relationship. 'Thermometer : Temperature' is measurement, not 'tool : material'. Reject pairs that share words loosely but not the core logic. Confirm both relationship type and direction before locking your answer.