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11CHAPTER

Syllogism & Venn Diagrams

"Sab billiyan kutte hain…" β€” sach-jhooth se matlab nahi, sirf tark se! Gol ghere banao. β­•β­•

Dosto, Syllogism mein kuch kathan (statements) diye jate hain aur kuch nishkarsh (conclusions) β€” batana hota hai ki nishkarsh kathanon se nikalta hai ya nahi.

Sabse zaroori baat pehle hi samajh lo: kathan sach hain ya jhooth, isse koi matlab nahi! "Sab billiyan kutte hain" duniya mein galat hai, par sawal mein use sach maan kar hi chalna hai. Sirf tark (logic) dekhna hai.

CET Group D mein isse 1–2 questions aate hain. Tarika bilkul pakka hai β€” Venn diagram (gol ghere) bana lo, aur jo har haal mein sach dikhe wahi answer. Chalo! πŸ’ͺ

1. ⭐ Char tarah ke kathan aur unke Venn diagram

"All A are B" B A A poora B ke andar "No A is B" A B Dono bilkul alag β€” koi mel nahi "Some A are B" A B Thoda hissa milta hai
Teen basic tasveerein. Chautha kathan "Some A are not B" = A ka kuch hissa B se bahar hai.
KathanMatlabVenn
All A are BA ka har sadasya B mein haiA, B ke andar
No A is BKoi bhi A, B nahi haiAlag-alag ghere
Some A are BA ka kam se kam ek sadasya B mein haiAapas mein katte hue
Some A are not BA ka kam se kam ek sadasya B mein nahiA ka kuch hissa bahar

2. ⭐ PAKKE NIYAM β€” ye sidhe nikal aate hain

βœ… Ye conclusions HAMESHA sahi hote hain β‘  All A are B + All B are C β†’ All A are C (aur Some C are A bhi βœ“)
β‘‘ Some A are B + All B are C β†’ Some A are C
β‘’ All A are B + No B is C β†’ No A is C
β‘£ No A is B + All C are A β†’ No C is B
β‘€ Ulta karna (conversion): All A are B β†’ Some B are A Β· No A is B β†’ No B is A Β· Some A are B β†’ Some B are A
❌ Ye kabhi nahi nikalte (INVALID) β‘  All A are B + Some B are C β†’ Some A are C βœ—
β‘‘ Some A are B + Some B are C β†’ Some A are C βœ—
β‘’ No A is B + No B is C β†’ No A is C βœ—
β‘£ All A are B β†’ All B are A βœ— (ulta karke "All" nahi banta, sirf "Some")
Do 'Some' wale kathanon se aur do 'No' wale kathanon se β€” kabhi pakka conclusion nahi banta.

3. Solved Example 1 β€” sabse common pattern

✏️ Kathan: (i) Sab billiyan kutte hain. (ii) Sab kutte paltu hain. Nishkarsh: (a) Sab billiyan paltu hain. (b) Kuch paltu billiyan hain.
Venn: billi ka ghera β†’ kutte ke andar β†’ wo dono paltu ke andar
(a) Billi poori paltu ke andar hai β†’ sahi βœ“
(b) Billiyan paltu ke andar hain, matlab kuch paltu to billi hain hi β†’ sahi βœ“
Answer: dono nishkarsh sahi hain.

4. Solved Example 2 β€” jahan log fasste hain

✏️ Kathan: (i) Sab pen kitaab hain. (ii) Kuch kitaab kagaz hain. Nishkarsh: Kuch pen kagaz hain.
Soch: "Kuch kitaab kagaz hain" β€” ho sakta hai wo kuch kitaab pen wale hisse se bilkul alag hon!
Venn banao: pen ka ghera kitaab ke andar, aur kagaz kitaab ke doosre kone ko kaat raha ho β€” tab koi pen kagaz nahi hoga.
Answer: Nishkarsh nahi nikalta βœ— (ye is chapter ka sabse bada trap hai!)

5. Solved Example 3 β€” negative wala

✏️ Kathan: (i) Sab kitaab pen hain. (ii) Koi pen pencil nahi hai. Nishkarsh: Koi kitaab pencil nahi hai.
Venn: kitaab poori pen ke andar; pen ka ghera pencil se bilkul alag β†’ to kitaab bhi pencil se alag hi rahegi
Answer: Sahi βœ“ (All + No = No wala pakka niyam)

6. "Either–Or" wala case (thoda advance)

πŸ“Œ Kab "ya to ye ya wo" wala answer aata hai Jab do nishkarsh alag-alag to galat hon, par dono milke saari possibility cover kar lein (jaise "Some A are B" aur "No A is B"), tab answer hota hai "either (a) or (b) follows".
Pehchan: dono nishkarsh ek hi jodi (A aur B) par hon aur ek positive ho doosra negative.
✏️ Type 1 β€” Do kathan, do nishkarsh Sabse common. Har nishkarsh ko alag-alag jaancho: "kya ye har tasveer mein sach hai?" Ek bhi tasveer mein galat = nishkarsh nahi nikalta.
✏️ Type 2 β€” "All + All" wala (sabse aasan) All A are B + All B are C β†’ All A are C aur Some C are A dono sahi. Ye pakka scoring sawal hai.
✏️ Type 3 β€” "Some" wala trap Do 'Some' kathanon se kabhi pakka conclusion nahi banta. Aisa dikhte hi "does not follow" ki taraf jhuk jao.
✏️ Type 4 β€” Conversion (ulta karna) "All A are B" se Some B are A nikalta hai (All B are A nahi). "No A is B" se No B is A nikalta hai. Ye chhota niyam kai sawal solve kar deta hai.
✏️ Type 5 β€” Either–Or Dono nishkarsh alag-alag galat par ek hi jodi par positive+negative β†’ answer "either (a) or (b)". Kam aata hai par aaye to yaad rahe.
Trick 1: Duniya ka gyaan bhool jao
Kathan ko SACH maan ke chalo
"Sab billiyan kutte hain" galat lagta hai β€” par sawal mein use sach maan ke hi tark lagana hai. Apni jaankari yahan dushman hai!
Trick 2: Ghere banao, sochne mein waqt mat gawao
2-3 gol ghere = answer
Dimaag mein sochne se confusion hoti hai. 10 second mein tasveer banao β€” nishkarsh saamne dikh jayega.
Trick 3: "Kya koi AUR tasveer ban sakti hai?"
Ek tasveer kaafi nahi
Nishkarsh tabhi sahi hai jab wo har possible tasveer mein sach ho. Ek aisi tasveer bana lo jisme wo galat ho β€” mil gayi to answer "does not follow".
Trick 4: 'Some' + 'Some' = kuch nahi
Do 'Some' β†’ koi conclusion nahi
Aise hi do negative (No + No) se bhi kuch nahi nikalta. Ye do line kai sawal 5 second mein khatam kar deti hain.
Trick 5: Ulta karne ka niyam
All β†’ Some Β· No β†’ No Β· Some β†’ Some
"All A are B" ka ulta Some B are A hai. Bahut se sawalon mein bas yahi poocha jata hai.
❌ Galti 1: Apni jaankari (general knowledge) laga dena "Sab billiyan kutte hain" par ruk mat jao. Sawal sach-jhooth nahi, tark pooch raha hai.
❌ Galti 2: 'All' ko ulta kar dena "All A are B" se All B are A NAHI nikalta β€” sirf Some B are A. Sab aam ko fal kehte hain, par har fal aam nahi hota.
❌ Galti 3: Sirf ek tasveer bana ke answer de dena Ek tasveer mein nishkarsh sach dikh sakta hai, par doosri mein galat. Har tasveer mein sach hona chahiye β€” tabhi "follows".
❌ Galti 4: 'Some' se 'All' bana dena "Kuch A, B hain" ka matlab ye nahi ki "sab A, B hain". Aur "Some A are B" hone par bhi "Some A are not B" pakka nahi hota.
❌ Galti 5: Dono nishkarsh ek saath jaanchna Har nishkarsh ko alag-alag jaancho. Ek sahi ho sakta hai aur doosra galat β€” options mein "only (a) follows" jaisa vikalp isi liye hota hai.
Syllogism mein kathan sach hain ya nahi?tap πŸ‘†
Fark nahi padta β€” sach maan ke chalo
Solve karne ka tarika?tap πŸ‘†
Venn diagram (gol ghere) banao
All A are B + All B are C β†’ ?tap πŸ‘†
All A are C βœ“ (Some C are A bhi βœ“)
Some A are B + All B are C β†’ ?tap πŸ‘†
Some A are C βœ“
All A are B + No B is C β†’ ?tap πŸ‘†
No A is C βœ“
All A are B + Some B are C β†’ Some A are C?tap πŸ‘†
Nahi nikalta βœ— (bada trap)
Some + Some se kya nikalta hai?tap πŸ‘†
Kuch bhi nahi
No + No se kya nikalta hai?tap πŸ‘†
Kuch bhi nahi
"All A are B" ka ulta?tap πŸ‘†
Some B are A (All B are A nahi!)
"No A is B" ka ulta?tap πŸ‘†
No B is A βœ“
"Some A are B" ka ulta?tap πŸ‘†
Some B are A βœ“
"All A are B" ka Venn?tap πŸ‘†
A ka ghera B ke andar
"No A is B" ka Venn?tap πŸ‘†
Alag-alag ghere
"Some A are B" ka Venn?tap πŸ‘†
Katte hue (overlap) ghere
Nishkarsh kab "follows" hota hai?tap πŸ‘†
Jab har possible tasveer mein sach ho
"Either–or" kab aata hai?tap πŸ‘†
Ek hi jodi par positive + negative nishkarsh
Dono nishkarsh kaise jaanche?tap πŸ‘†
Alag-alag, ek saath nahi
Is chapter ka sabse bada dushman?tap πŸ‘†
Apni general knowledge
Kathan jodiNikalta hai?
All + AllAll βœ“ (aur Some ulta bhi βœ“)
Some + AllSome βœ“
All + NoNo βœ“
No + All (ulta kram)No βœ“
All + SomeKuch nahi βœ—
Some + SomeKuch nahi βœ—
No + NoKuch nahi βœ—
All A are B ka ultaSome B are A
No A is B ka ultaNo B is A
Some A are B ka ultaSome B are A
Nishkarsh "follows" kabHar tasveer mein sach ho
Sabse badi galtiApni jaankari lagana
🎯 Score: 0 / 0 Total questions: 14
Practice (exam-style)

Q1. Statements: All cats are dogs. All dogs are pets. Conclusion: All cats are pets.

πŸ’‘ All + All = All β†’ billi ka ghera kutte ke andar, kutta paltu ke andar.
Practice (exam-style)

Q2. Statements: All cats are dogs. All dogs are pets. Conclusion: Some pets are cats.

πŸ’‘ Billiyan paltu ke andar hain β†’ kuch paltu billi hain hi (ulta karne ka niyam).
Practice (exam-style)

Q3. Statements: All pens are books. Some books are papers. Conclusion: Some pens are papers.

πŸ’‘ Wo "kuch kitaab" pen wale hisse se alag ho sakti hain β†’ pakka nahi (All + Some = kuch nahi).
Practice (exam-style)

Q4. Statements: Some pens are books. All books are papers. Conclusion: Some pens are papers.

πŸ’‘ Some + All = Some βœ“ β€” jo pen kitaab hain wo kagaz bhi honge.
Practice (exam-style)

Q5. Statements: No man is a woman. All boys are men. Conclusion: No boy is a woman.

πŸ’‘ Boys, men ke andar; men ka ghera woman se alag β†’ boy bhi woman se alag.
Practice (exam-style)

Q6. Statement: All roses are flowers. Which conclusion follows?

πŸ’‘ "All" ka ulta hamesha "Some" hota hai β†’ Some flowers are roses.
Practice (exam-style)

Q7. Statement: All roses are flowers. Conclusion: All flowers are roses.

πŸ’‘ Sab gulab phool hain, par har phool gulab nahi β€” 'All' ulta nahi hota.
Practice (exam-style)

Q8. Statement: No cat is a dog. Conclusion: No dog is a cat.

πŸ’‘ "No" ulta karne par bhi "No" hi rehta hai (dono ghere alag hain).
Practice (exam-style)

Q9. Statement: Some students are girls. Conclusion: Some girls are students.

πŸ’‘ "Some" dono taraf chalta hai β€” overlap dono ke liye same hai.
Practice (exam-style)

Q10. Statements: Some students are girls. Some girls are dancers. Conclusion: Some students are dancers.

πŸ’‘ Do 'Some' kathanon se kabhi pakka conclusion nahi nikalta.
Practice (exam-style)

Q11. Statements: No cat is a dog. No dog is a cow. Conclusion: No cat is a cow.

πŸ’‘ Do negative (No + No) kathanon se kuch nahi nikalta β€” cat aur cow overlap kar sakte hain.
Practice (exam-style)

Q12. Statements: All books are pens. No pen is a pencil. Conclusion: No book is a pencil.

πŸ’‘ All + No = No βœ“ (book poori pen ke andar, pen pencil se alag).
Practice (exam-style)

Q13. In syllogism, a conclusion "follows" only when it is true:

πŸ’‘ Har possible Venn tasveer mein sach ho β€” tabhi "follows".
Practice (exam-style)

Q14. Which combination of statements can NEVER give a definite conclusion?

πŸ’‘ Do 'Some' (aur do 'No') kathanon se kabhi pakka conclusion nahi banta.

Syllogism mein apni jaankari bhool jao β€” kathan ko sach maan ke sirf tark lagao, aur Venn ghere bana lo. Pakke niyam: All + All = All (aur ulta Some βœ“), Some + All = Some, All + No = No. Jo kabhi nahi nikalte: All + Some, Some + Some, aur No + No. Ulta karne ka niyam yaad rakho β€” "All A are B" se sirf Some B are A banta hai, "All B are A" nahi. Aur sabse zaroori kasauti: nishkarsh tabhi "follows" jab wo har possible tasveer mein sach ho β€” isliye hamesha sochΠΎ "kya koi aisi tasveer ban sakti hai jisme ye galat ho?" πŸš€