Syllogism by Rules Part 3: Actual Rules Syllogism

Shortcut to solve syllogism by rules

Day 3: Actual Rules Syllogism


Rule Table: Learn it so that next time you don’t have to refer this table

S.No First Proposition Second Proposition Conclusion
10 Some Not Anything(Some/No/All/Some Not) NO CONLCUSION*
*No Conclusion= Any Possibility is True

Note that we will have to use the concept of Rearrangement and Reversal that we have learned on Day 1 and Day 2 to solve Syllogism by rules.


1) All+All=All

All Red are Green + All Green are Blue. => Conclusion=  All Red is Blue
Note: The reverse of the obtained conclusion i.e Reverse of All Red is Blue = Some Blue is Red will also be true.

2) All + No= No

All Red is green + No Green is Blue => Conclusion= No Red is blue.
Reverse conclusion= No Blue is Red

3) All+Some=No Conclusion

All Red is Green + Some Green is Blue => Conclusion= No conclusion can be drawn between Red And Blue. (But No conclusion means that any possibility between Red and Blue will be true)
Example: All Red being blue is a possibility.
Some Red are blue is a possibility
Some red are not blue is a possibility
No red is blue is a possibility.
All these possibility are true.

4) Some + All= Some 
Some Red is green + All green is blue. => Conclusion= Some Red is blue.
Reverse conclusion=some blue is red.

5) Some + No = Some Not

Some Red is green + No green is blue=> Conclusion= Some Red is Not Blue

6) Some + Some= No Conclusion

Some Red is Green + Some Green is blue. => Conclusion= No Conclusion = Any possibility between Red and Blue is true (Same as in (3))

7) No + All = Some Not Reversed
No Red is Green + All Green is blue => (Apply Some Not on Reversed entity. i.e reverse Red and blue)
Means First Blue then Red at last and put Some Not
=> Conclusion= Some Blue are Not Red

8) No + Some = Some Not Reversed
No Red is Green + Some Green is blue => Conclusion= Some Blue is not Red

9) No + No = No
No Red is Green + No Green is blue => No Conclusion.

Exercise for the Day

Solve only by rules. Don’t use venn diagram.

  1. Statement:
    (a) Some A are B
    (b) All A are C
    (i) Some B are C
    (ii) Some C are A
    (iii) Some B are A
    A) Only (i)
    B) Only (ii)
    C) Both (i) and (ii)
    D) Both (ii) and (iii)
    E) All
    View Answer
    Option E
    : For (i) => reverse(a) + (b) => Some B are A+ All A are C => Some + All= Some => Some B are C is true.
    For (ii) true by reverse of (b) . For (iii) True by reverse of (a)
  2. Statement:
    (a) No pink is white
    (b) All white is red
    (i) Some red are not pink
    (ii) Some pink are not red
    A) Only (i)
    B) Only (ii)
    C) Either
    D) Both
    E) Neither
    View Answer
    Option A
    : No+All = Some not reversed=> Some red are not pink.
    Please Note: Some A are not B DOESNOT MEANS THAT Some B are Not A.
  3. Statement:
    (a) All A are B.
    (b) Some C are B
    (i) All A are C
    (ii) Some A are C
    (iii) All A are C is a possibility
    A) Only (i)
    B) Only (ii)
    C) Only (iii)
    D) None follows
    View Answer
    Option C
    : For FIRST & LAST RULE to be applicable. We have to reverse (b). So we get
    All A are B + Some B are C => All+ Some = No conclusion between A and C => any possibility between A and C is true. So only (iii) is true.
  4. Statement:
    (a)Some Samsung are Phone
    (b) No Samsung is Vivo.
    (i) Some Vivo are not phone
    (ii) Some Phone are not Vivo
    (iii) No Vivo is samsung
    A) (i) and (iii)
    B) (iii)
    C) (ii) and (iii)
    D) (ii)
    E) All
    View Answer
    Option C
    : For (ii): Reverse any of the two statement, as the preference of both are equal. Here I am reversing (a). So we get=> Some Phone are Samsung + No samsung is vivo => Some + No = Some Not => Some phone are not vivo. So (ii) is true. You can try by reversing (b). The conclusion will be same.
    For (iii) It is the reverse of (b). So true
  5. Statement:
    (a) Some A are B
    (b) Some B are C
    (i) Some A are C
    (ii) No A is C is a possiblity
    (iii) Some C are B
    A) Only (ii)
    B) Only (iii)
    C) Only (i)
    D) None
    E) Both (ii) and (iii)
    View Answer
    Option E
    : For (ii) we have Some + Some = No conclusion between A and C. So any possibility is true between A and C. So (ii) is true.
    (iii) is true by reverse of (b)

Topic for Day 4: Use of rules to solve more than 2 statements simultaneously.

Ask your doubt in comment section.

Thank You!!!!!


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71 Thoughts to “Syllogism by Rules Part 3: Actual Rules Syllogism”

  1. Dipankar

    thyanku sir

  2. paakhi

    Yad kese hoga ye table ? 🙁

    1. Suraj

      yaad karna padega,, roz roz yaad karo 1 week.. ho jayega

      1. paakhi

        Sir practice questions provide kr dijiye

        1. Suraj

          ok,, abhi 2 minute me upar yehi post krta hu

    2. Yogi ji

      Venn se aata hai to waise bhi kr sakte

      1. paakhi

        Wo to aata hi i want to learn this new one..then i ll compare

      2. Suraj

        ha kar sakte hai,, baat sirf time ki hai,, ek baar ye method aa jaye to 1/3 time lagega uska

  3. Yogi ji

    Some not wala ques deta Hu ek. Some not wale nhi aate

  4. Suraj

    Tell which conclusion follows in these 10 questions:
    1) Statements:
    Some A are B
    All B are C

    I. Some A are C
    II. Some C are A

    2) Statements:
    All Red are Blue
    No Blue is Pink

    I. No red is Pink
    II. Some Pink is blue

    3) Statements:
    Some banana is guava
    No guava is grapes

    I. Some banana are not grapes
    II. Some grapes are not banana

    4) Statements:
    No mobile is Phone
    Some Phone are Vivo

    I. Some Vivo are not mobile
    II. No phone is Mobile

    5) Statements:
    No A is B
    All B is Z

    I. Some Z is A
    II. Some Z is not A

    6) Statements:
    Some mouse is rat
    Some rat is cat

    I. Some cat is mouse is a possibility
    II. Some cat is not mouse is a possibility

    7) Statements:
    All A is B
    Some B is C

    I. Some A is C
    II. No A is C is a possibility

    8) Statements:
    No time is watch
    No watch is clock

    I. No time is clock
    II. No clock is watch

    9) Statements:
    All time is clock
    All clock is watch

    I. All time is watch
    II. Some watch is time

    10) Statements:
    All B is C
    Some A is B

    I. Some A is C
    II. All A are C

    1. paakhi


      1. Suraj

        3 is correct
        and for 4) both are correct because see the second conclusion is the reverse of 1st statement.. so it is also a conc.

    2. paakhi

      6– both

    3. paakhi


      1. Suraj

        7) correct
        8) only II.. again reverse wala concept

    4. paakhi


      1. Suraj

        9) both
        10) ques me misprint hai…will edit it

      2. Suraj

        10 me I follow krega

    5. Van Heusen

      10 – only 1
      9- both
      8- only 2
      7-only 2
      5-only 2

    6. rs

      1- neither
      2 only first

      3 first only
      4 first only
      5 second only
      6 both
      7 second only
      8 second only
      9 both
      10 first only

      1. Suraj

        1) Both I and II
        2) Answer: Only I
        3) Answer: Only I
        4) Answer: Both I and II
        5) Answer: Only II
        6) Answer: Both
        7) Answer: Only II
        8) Answer: Only II
        9) Answer: Both
        10) Answer: Only I

        1. Stoic

          sir in ques no.9 jaise apan ques 1 me conclusion k baad agr conclusion k reserve bnta h to wo true kr rhe h to 9th ques me b agr “some time is watch” hota to crct hota?

        2. Stoic

          i mean to say some time is watch ek aur additional conclusion hota tb

          1. Suraj

            yes yes, wo bhi true hota

    7. Yogi ji

      3 Ka second correct

    1. Yogi ji

      Some not wale btao

      1. Suraj

        jin do entoty k bech relation nikalna hai unko arrange karo pehle FIRST LAST RULE k babis pe, jo ki first two day sikhaya gaya hai,, then using todays rule find the relation.
        for example to check conclusion C) i.e between pen and paper. we need 3rd and 4th statement
        i.e .all pen are pencil .no pencil is paper
        All +No= no
        => no pen is paper
        => some pen is not paper is also true

        1. Yogi ji

          Some pen is not paper possiblty

          1. Suraj

            nhi True conclusion k aage possibilty lag jaye to wo false hoga..
            so Some pen is not paper possiblty is false

        2. paakhi

          Sir first option dekho—
          Book n pencil me relation diya hai..question se 1 n 3 statement use krke some book is pencil aara hai bt answer me mark ni hai kyu?

          1. Yogi ji

            Because Wrng find krna hai

          2. paakhi

            To instruction post kyu ni kiya u ne?

          3. Yogi ji

            Kaun sa quiz kra rha. Only prob puchni thi bus

  5. Yogi ji

    Kha hai new post

    1. Suraj

      isse post me hai some not ka case.. puri post padho..

      1. Yogi ji

        Niche check my ques

  6. Yogi ji

    Laxmi Vilas bank pvt ya govt

  7. paakhi

    @sir question 4 jo aapne abi post kiye hai–
    No+some–some not reverse
    1 option correct
    N some not ka reverse ni hota to answer should b 1st only na?
    U r sayin both how?

    1. Yogi ji

      Dono hai. No mobile is phone also true

    2. Suraj

      No mobile is Phone
      Some Phone are Vivo

      I. Some Vivo are not mobile
      II. No phone is Mobile

      I. is true by ur logic

      II. is true by reverse of :No mobile is Phone
      No A is B=> reverse => NO B is A
      No mobile is phone=> no phone is mobile

      1. paakhi

        Oks..statement individual ka reverse hai..nw got it

        1. Suraj

          yes ye,, us reverse ka ye bhi use hai.. coz agar dhyan se dekho to ye FIRST and LAST RULE ka hi part hi,, jinke bech me relation dekhna hai,, usme se ek first hona chahye ek last,, to ye ek hi sentence k first and last me hai.. to reverse wala concept aise case me dekha karo

          1. Suraj

            ok if u have any other doubt post it,, i will tell it tomorrow

  8. paakhi

    Got further doubts..good night

  9. sachin shukla@Target sbi po

    (a) No pink is white
    (b) All white is red
    (i) Some red are not pink
    (ii) Some pink are not red
    A) Only (i)
    B) Only (ii)
    C) Either
    D) Both
    E) Neither
    sir isme 2 q nahi follow krta plzz explain

    1. Suraj

      Statements are: No pink is white+ All white is red
      it is in the form No+All = SOme not reverse
      yani ki jo last me term hai usko pehle likho i.e Red aur jo pehle hai usse last me likho means pink and add SOme not
      so it becomes
      Some red are not pink


        Yes cleared doubt thanx a lot sir 🙂

  10. Stoic

    @surajskt:disqus sir

    1. Stoic

      If possibility case reverse me ho tb b follow krega na as in example 3 reverse ho red and blue to like
      All blue being red is possibility
      Some blue are red is possibility
      Some blue are not red is possibility
      No blue is red is possibility
      #ye sb true hoga na conclusion me?


        Yes this is same as rule no 6 if we apply reverse logic , thanx a lot @suraj sir

  11. ...........

    thanks az

  12. vinay

    Sir agar all/some/no + some not aa jaye to conclusion kya hoga?

    1. Suraj

      No conclusion hoga.. there are only two sepcial case with some not + all jisme conclusion niklega,, u can check them here :

      1. Trisha

        can you or @Shubhra_AspirantsZone:disqus mam please help in understanding critical reasoning rules / concept. mostly i get confuse in 2 options and choose the wrong one. please help if possible

  13. Ragul Kishore

    Sir i have a major dbt
    Statements : All leaves are roots. Some leaves are branches.
    Conclusions : I. Some branches are not leaves.
    II. Atleast some roots are branches.
    How to slove this ??
    The ans is only 2 follows

    1. Learnie

      conclusion one doesn’t follow as per rule some A is B can be written as some B is A here conclusion some branches are not leaves this cant be converted
      if it is possibility then ok if not then it doesn’t follow

      2 conclusions follows – write some branches are leaves and all leaves are roots – cut the leaves then it will be some + all = some so some branches are roots

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