Question 1

Syllogism validity test: from the statements 'No women teacher can play' and 'Some women teachers are athletes', determine which conclusion logically follows about male athletes and athletes in general being able to play

Accepted Answer

Given data Premise 1: No women teacher can play. Premise 2: Some women teachers are athletes. Conclusions tested: I: Male athletes can play. II: Some athletes can play. Concept/Approach Standard Venn/syllogism analysis: conclusions must necessarily follow. We cannot infer properties of male athletes from premises about women teachers. Also, from the given, the identified athletes (women teachers) are exactly those who cannot play; nothing guarantees that some athletes can play. Step-by-step reasoning 1) Premises tell us about women teachers only, not about male athletes → I does not follow.2) 'Some athletes can play' needs a guaranteed playing subset; our known athlete subset (women teachers) cannot play. Others may or may not; not necessary → II does not follow. Verification/Alternative Construct a model: Let all athletes be women teachers; then, by Premise 1, no athlete can play. In this model, I and II are false, proving they are not necessary conclusions. Common pitfalls Assuming existence of male athletes without support. Confusing possibility with necessity in syllogisms. Final Answer Neither I nor II follows.

Question 2

Syllogism with shared superset: 'All bags are cakes' and 'All lamps are cakes' — decide whether it necessarily follows that some lamps are bags or that no lamp is a bag (evaluate the valid either–or inference)

Accepted Answer

Given data Premise 1: All bags ⊆ cakes. Premise 2: All lamps ⊆ cakes. Conclusions: I: Some lamps are bags. II: No lamp is a bag. Concept/Approach Both sets (bags, lamps) are contained in the larger set (cakes). Their mutual relation is undetermined by the premises: they may overlap or be disjoint. In classical syllogism tests, such a pair forms a valid 'either–or' conclusion: exactly one of 'some overlap' or 'no overlap' must be true in any model, though we cannot say which. Step-by-step reasoning 1) From the premises alone, both intersection and disjoint models are possible.2) Since I and II are mutually exclusive and together exhaustive, the correct inference form is 'Either I or II follows'. Verification/Alternative Model A (overlap): some lamps are bags ⇒ I true, II false. Model B (disjoint): no lamp is a bag ⇒ II true, I false. In all models, one (and only one) holds. Common pitfalls Marking 'neither' because each individually is not necessary, forgetting the accepted either–or rule in such problems. Final Answer Either I or II follows.

Question 3

Two-premise syllogism on colour and price: 'All mangoes are golden in colour' and 'No golden-coloured things are cheap' — judge whether all mangoes are cheap or whether golden-coloured mangoes are not cheap

Accepted Answer

Given data Premise 1: All mangoes ⇒ golden-coloured. Premise 2: No golden-coloured thing ⇒ cheap. Conclusions: I: All mangoes are cheap. II: Golden-coloured mangoes are not cheap. Concept/Approach Classical syllogism chain: All A are B; No B are C → No A are C. Step-by-step reasoning 1) Mangoes ⊆ golden.2) golden ∩ cheap = ∅.3) Hence mangoes ∩ cheap = ∅ → mangoes are not cheap (which is exactly II).4) I contradicts the derived conclusion; therefore I does not follow. Verification/Alternative Venn diagram confirms mango set lies entirely within non-cheap region. Common pitfalls Confusing 'no B are C' with 'some B are not C'. Final Answer Only conclusion II follows.

Question 4

Syllogism chain reasoning: given 'Some kings are queens' and 'All queens are beautiful', determine whether it follows that all kings are beautiful or that all queens are kings

Accepted Answer

Given data Premise 1: Some kings are queens. Premise 2: All queens are beautiful. Conclusions: I: All kings are beautiful. II: All queens are kings. Concept/Approach From 'Some K are Q' and 'All Q are B', the valid derived conclusion is 'Some kings are beautiful'. However, neither of the provided universal conclusions is justified. Step-by-step reasoning 1) Some K ∩ Q ≠ ∅ and Q ⊆ B → Some K ⊆ B (particular conclusion).2) I (All K ⊆ B) overgeneralizes from 'some' → not valid.3) II (All Q ⊆ K) is converse; not supported. Verification/Alternative Countermodel: Let K have members {k1,k2}, Q = {k1}, B contain Q and others. Then 'some K are B' true, I and II false. Common pitfalls Illicit conversion of 'some' to 'all'. Assuming symmetry between classes K and Q. Final Answer Neither I nor II follows.

Question 5

Syllogism and logical deduction practice (Venn diagram method): Given the statements 'Some doctors are fools' and 'Some fools are rich', determine which of the conclusions — (I) 'Some doctors are rich' and (II) 'Some rich are doctors' — logically fo…

Accepted Answer

Given data Premise 1: Some doctors are fools. Premise 2: Some fools are rich. Conclusions to test: (I) Some doctors are rich. (II) Some rich are doctors. Concept/Approach In categorical syllogisms, two particular ('Some') premises with the same middle term do not guarantee overlap between the two end terms. Use Venn diagrams or counterexample construction to check necessity versus possibility. Step-by-step evaluation 1) Draw three sets: Doctors (D), Fools (F), Rich (R).2) Place an 'X' in the intersection D∩F to represent 'Some doctors are fools' (at least one element).3) Place another 'X' in F∩R (not necessarily the same spot) for 'Some fools are rich'.4) There is no compulsion that the two X's coincide; hence there may be no element in D∩R.5) Therefore, neither 'Some doctors are rich' nor its symmetric 'Some rich are doctors' follows with certainty. Verification/Alternative Create a countermodel: Let the doctor-fool individual be a (not rich) and the fool-rich individual be b (not a doctor). Both premises are true; D∩R remains empty, so both conclusions fail — proving non-necessity. Common pitfalls Confusing 'possible' with 'must be true' — both conclusions are possible but not compelled. Assuming transitivity across 'Some' statements; it does not hold. Final Answer Neither I nor II follows.

Question 6

Syllogism validity check with universal–particular mix: From 'All roads are waters' and 'Some waters are boats', decide which conclusions — (I) 'Some boats are roads' and (II) 'All waters are boats' — follow logically and necessarily.

Accepted Answer

Given data Premise 1: All roads are waters (Roads ⊆ Waters). Premise 2: Some waters are boats (∃ Waters ∩ Boats). Test: (I) Some boats are roads. (II) All waters are boats. Concept/Approach A particular statement about Waters→Boats does not ensure the particular elements are those that are Roads. Also, a universal statement 'All waters are boats' cannot be derived from 'Some waters are boats'. Step-by-step evaluation 1) Roads are a subset of Waters.2) At least one Water is a Boat; this could be a water element that is not a Road.3) Hence (I) 'Some boats are roads' is not forced; may be false in some models.4) (II) upgrades 'Some' to 'All' — an invalid generalization. Verification/Alternative Countermodel: Let Waters = {w1, w2}, Roads = {w1}, Boats = {w2}. Then all premises hold; (I) and (II) are both false. Thus neither conclusion is necessary. Common pitfalls Assuming the 'Some waters are boats' elements lie inside Roads without proof. Illicit conversion from 'Some' to 'All'. Final Answer Neither I nor II follows.

Question 7

Negative–negative syllogism analysis: Using 'No bat is ball' and 'No ball is wicket', determine whether (I) 'No bat is wicket' and (II) 'All wickets are bats' follow with logical certainty.

Accepted Answer

Given data Premise 1: No bat is ball (Bat ∩ Ball = ∅). Premise 2: No ball is wicket (Ball ∩ Wicket = ∅). Test: (I) No bat is wicket. (II) All wickets are bats. Concept/Approach Two negative premises about the same middle term (Ball) do not establish any relation between the two end terms (Bat and Wicket). A Venn check or counterexample settles necessity. Step-by-step evaluation 1) Both statements forbid overlap with Ball, but say nothing about Bat–Wicket overlap.2) It remains possible that some bats are wickets (or none are), i.e., relation is undetermined.3) (II) is an extreme universal claim with no support. Verification/Alternative Countermodel: Let Bat = {b1}, Wicket = {b1}, Ball = {c1}. Then premises hold (neither Bat nor Wicket intersects Ball), but (I) is false and (II) is false. Hence neither conclusion is compelled. Common pitfalls Illicit inference 'No bat is wicket' merely because both avoid Ball. Final Answer Neither I nor II follows.

Question 8

Universal–universal with exclusion: From 'All flowers are trees' and 'No fruit is tree', assess whether the conclusions (I) 'No fruit is flower' and (II) 'Some trees are flowers' follow beyond doubt in standard syllogism.

Accepted Answer

Given data Premise 1: All Flowers ⊆ Trees. Premise 2: No Fruit is a Tree (Fruit ∩ Tree = ∅). Conclusions: (I) No Fruit is a Flower. (II) Some Trees are Flowers. Concept/Approach (I) is a standard syllogistic inference: if Flowers are among Trees and Fruits are excluded from Trees, then Fruits are excluded from Flowers. (II) is an existential import commonly assumed in aptitude syllogisms: if 'All Flowers are Trees' and Flowers exist, then at least some Trees are Flowers. Step-by-step calculation/logic 1) From Premise 1, Flower ⊆ Tree.2) From Premise 2, Fruit ∩ Tree = ∅ ⇒ Fruit cannot overlap any subset of Tree, including Flowers.3) Hence (I) 'No Fruit is Flower' is compelled.4) If at least one Flower exists (typical test assumption), that Flower is a Tree ⇒ 'Some Trees are Flowers' (II) holds. Verification/Alternative Venn diagram: put Flowers wholly inside Trees; draw Fruit disjoint from Trees. Then both conclusions are visually evident. Common pitfalls Rejecting (II) due to confusion about existential import; aptitude syllogism sets usually accept it. Final Answer Both I and II follow.

Question 9

Chain reasoning with two universals: Given 'Every minister is a student' and 'Every student is inexperienced', determine which conclusions — (I) 'Every minister is inexperienced' and (II) 'Some inexperienced are students' — are necessarily true.

Accepted Answer

Given data Premise 1: Minister ⊆ Student. Premise 2: Student ⊆ Inexperienced. Test: (I) Minister ⊆ Inexperienced. (II) Some Inexperienced are Students. Concept/Approach Subset chaining: if A ⊆ B and B ⊆ C, then A ⊆ C. For (II), if there exists at least one student (a standard assumption in these items), that student is inexperienced, yielding a 'Some' statement. Step-by-step evaluation 1) From Premise 1 and 2: Minister ⊆ Student ⊆ Inexperienced ⇒ Minister ⊆ Inexperienced ⇒ (I) holds.2) Existence: Since ministers exist in the scenario, there exists at least one student; therefore 'Some inexperienced are students' ⇒ (II) holds. Verification Draw nested sets: Minister inside Student, inside Inexperienced; conclusions are immediate. Common pitfalls Missing the existence cue that supports the 'Some' conclusion. Final Answer Both I and II follow.

Question 10

Syllogism with universal and negative premises: From 'All roads are poles' and 'No pole is a house', decide whether the conclusions (I) 'Some roads are houses' and (II) 'Some houses are poles' can be affirmed as logically necessary.

Accepted Answer

Given data Premise 1: Roads ⊆ Poles. Premise 2: Poles ∩ Houses = ∅. Conclusions: (I) Some Roads are Houses. (II) Some Houses are Poles. Concept/Approach If no Pole is a House, then any subset of Poles (including Roads) has empty intersection with Houses. Particular claims asserting such intersections are false. Step-by-step evaluation 1) From Premise 2, Poles and Houses are disjoint.2) Since Roads ⊆ Poles, Roads ∩ Houses = ∅ ⇒ (I) cannot hold.3) Directly, 'Some Houses are Poles' contradicts Premise 2 ⇒ (II) cannot hold. Verification Venn diagram readily shows disjointness between Poles and Houses, eliminating both conclusions. Common pitfalls Overlooking that a subset (Roads) inherits disjointness from its superset (Poles). Final Answer Neither I nor II follows.

Question 11

Complementary negatives with a subset: Using 'All fish are tortoise' and 'No tortoise is a crocodile', determine whether the conclusions (I) 'No crocodile is a fish' and (II) 'No fish is a crocodile' both follow in standard syllogistic logic.

Accepted Answer

Given data Premise 1: Fish ⊆ Tortoise. Premise 2: Tortoise ∩ Crocodile = ∅. Conclusions: (I) No Crocodile is a Fish. (II) No Fish is a Crocodile. Concept/Approach If Fish are entirely within Tortoise and Tortoise and Crocodile are disjoint, then Fish and Crocodile are also disjoint. 'No S are P' is symmetric, so both formulations are true. Step-by-step evaluation 1) Fish ⊆ Tortoise and Tortoise ∩ Crocodile = ∅ ⇒ Fish ∩ Crocodile = ∅.2) Therefore: (II) 'No Fish is a Crocodile' is true.3) Symmetrically: (I) 'No Crocodile is a Fish' is also true. Verification Diagram Fish inside Tortoise; separate Crocodile set disjoint from Tortoise. No overlap with Fish either way; both conclusions stand. Common pitfalls Believing only one of the symmetric 'No' statements holds; both are equivalent. Final Answer Both I and II follow.

Question 12

Particular–universal with common middle: Given 'Some dedicated souls are angels' and 'All social workers are angels', analyze whether the conclusions (I) 'Some dedicated souls are social workers' and (II) 'Some social workers are dedicated souls' ar…

Accepted Answer

Given data Premise 1: Some Dedicated Souls ⊆ Angels (particular inclusion). Premise 2: Social Workers ⊆ Angels (universal inclusion). Conclusions: (I) Some Dedicated Souls are Social Workers. (II) Some Social Workers are Dedicated Souls. Concept/Approach Sharing a common superset (Angels) does not force overlap between the two subsets. Particular conclusions about intersection need evidence of direct overlap, not merely co-membership of a larger set. Step-by-step evaluation 1) DS ⊆ Angels (for some elements), and SW ⊆ Angels.2) DS and SW might be disjoint subsets inside Angels.3) Therefore neither (I) nor (II) is necessary. Verification/Alternative Countermodel: Angels = {a1, a2}, DS = {a1}, SW = {a2}. Premises true; both conclusions false. Common pitfalls Assuming common membership implies intersection (subset fallacy). Final Answer Neither I nor II follows.

Question 13

Complementary statements about wealth and poverty: From 'No gentleman is poor' and 'All gentlemen are rich', decide whether the conclusions (I) 'No poor man is rich' and (II) 'No rich man is poor' necessarily follow.

Accepted Answer

Given data Premise 1: Gentleman ∩ Poor = ∅. Premise 2: Gentleman ⊆ Rich. Conclusions: (I) No Poor is Rich. (II) No Rich is Poor. Concept/Approach The premises restrict relations involving the subset 'Gentleman', not the entire sets 'Rich' or 'Poor'. Without information about non-gentlemen, we cannot generalize to all rich or all poor. Step-by-step evaluation 1) From Premise 1 & 2: Gentlemen are rich and not poor.2) But there may exist rich non-gentlemen who could or could not be poor (no info given).3) Hence both universal claims (I) and (II) are not derivable. Verification/Alternative Countermodel: Let Gentlemen = {g1}, Rich = {g1, r2}, Poor = {r2}. Premises hold (g1 rich, not poor), yet (I) is false (r2 is both rich and poor in a definitional sense) and (II) is false. Therefore no conclusion is necessary. Common pitfalls Overextending results from a subset (Gentleman) to the whole set (Rich/Poor). Final Answer Neither I nor II follows.

Question 14

Mixed particular and universal with attribute layering: Using 'Some swords are sharp' and 'All swords are rusty', test whether the conclusions (I) 'Some rusty things are sharp' and (II) 'Some rusty things are not sharp' must be true.

Accepted Answer

Given data Premise 1: Some Swords are Sharp (∃ Sword ∩ Sharp). Premise 2: All Swords are Rusty (Sword ⊆ Rusty). Conclusions: (I) Some Rusty things are Sharp. (II) Some Rusty things are not Sharp. Concept/Approach Map attributes: If a subset (Swords) lies entirely within Rusty, then any particular Sword (sharp or not) is a Rusty thing. From 'Some Swords are Sharp' it follows that some Rusty things (those sharp swords) are Sharp. But we cannot assert existence of non-sharp swords. Step-by-step evaluation 1) From Premise 2, every Sword is Rusty.2) Premise 1 gives at least one element that is both Sword and Sharp.3) Therefore that element is also Rusty ∧ Sharp ⇒ (I) holds.4) (II) requires an element that is Rusty but not Sharp; premises do not guarantee such an element (all swords could be sharp for all we know). Verification/Alternative Countermodel for (II): Let all Swords be Sharp; both premises hold, but there is no Rusty ∧ ¬Sharp element. Hence (II) is not necessary. Common pitfalls Assuming from 'Some swords are sharp' that some swords are not sharp; such a negation is unwarranted. Final Answer Only conclusion I follows.

Question 15

Syllogism and logical reasoning question on categorical statements: 'All fishes are grey in colour' and 'Some fishes are heavy' — determine which conclusions necessarily follow (All heavy fishes are grey; All light fishes are not grey)

Accepted Answer

Given data Premise 1: All fishes are grey in colour (Fish ⊆ Grey). Premise 2: Some fishes are heavy (∃ Fish ∩ Heavy). Conclusions to test: I: All heavy fishes are grey. II: All light fishes are not grey. Concept/Approach (why this method) Use standard categorical syllogism rules and set–subset reasoning. From 'All A are B', every member of A inherits property B. Particular existence ('Some') does not invert or extend universals to unrelated classes. Step-by-Step calculation / logic 1) From Premise 1, every fish is grey.2) 'Heavy fishes' are a subset of fishes (they are the fishes that are heavy).3) Therefore every heavy fish, being a fish, is grey ⇒ Conclusion I is necessarily true.4) 'Light fishes' are also fishes; since all fishes are grey, light fishes are grey, not 'not grey' ⇒ Conclusion II is false. Verification/Alternative Venn diagram: Put the entire Fish circle inside Grey. Any subcategory of Fish (Heavy-fish, Light-fish) lies inside Grey; hence I holds and II contradicts the diagram. Common pitfalls Misreading 'All fishes are grey' as 'Only fishes are grey' (not stated). Assuming 'light' excludes 'grey'; colour and weight are independent attributes. Final Answer Only conclusion I follows.

Question 16

Syllogism test on athletes: from 'All good athletes win' and 'All good athletes eat well', decide which conclusions must follow (All who eat well are good athletes; All who win eat well)

Accepted Answer

Given data Premise 1: All good athletes win (GoodAthlete ⟶ Win). Premise 2: All good athletes eat well (GoodAthlete ⟶ EatWell). Conclusions to test: I: All who eat well are good athletes (EatWell ⟶ GoodAthlete). II: All who win eat well (Win ⟶ EatWell). Concept/Approach (why this method) Chain only what is compelled by universals. Beware of illicit converse: from 'All A are B' you cannot infer 'All B are A'. Step-by-Step calculation / logic 1) From premises: GoodAthlete ⟶ Win and GoodAthlete ⟶ EatWell, hence GoodAthlete ⟶ (Win ∧ EatWell).2) Conclusion I flips Premise 2 (illicit converse), not guaranteed ⇒ false.3) Conclusion II extends 'Win' to everyone, but we only know a subset (good athletes) who win eat well ⇒ not necessary ⇒ false. Verification/Alternative Counterexample: Let some non-athletes eat well or win; premises permit this. Then I and II fail. Common pitfalls Assuming all winners are good athletes (overgeneralization). Conflating sufficient and necessary conditions. Final Answer Neither I nor II follows.

Question 17

Logical deduction with categories: 'All film stars are playback singers' and 'All film directors are film stars' — identify which conclusions necessarily follow (All directors are playback singers; Some film stars are directors)

Accepted Answer

Given data Premise 1: All film stars ⟶ playback singers. Premise 2: All film directors ⟶ film stars. Conclusions: I: All film directors ⟶ playback singers. II: Some film stars are film directors. Concept/Approach (why this method) Use transitivity of subset relations: If A ⊆ B and B ⊆ C, then A ⊆ C. Particular existence ('some') cannot be derived from two universal premises without an existential premise. Step-by-Step calculation / logic 1) Directors ⊆ Stars and Stars ⊆ Singers ⇒ Directors ⊆ Singers ⇒ Conclusion I is necessary.2) Conclusion II asserts existence ('some'); from two universals, it does not necessarily follow ⇒ not compelled. Verification/Alternative Model with zero directors: Premises still hold; Conclusion II ('some') fails. Hence II is not a necessary conclusion. Common pitfalls Assuming classes are non-empty without explicit statement. Believing a chain of universals implies a particular 'some' statement. Final Answer Only conclusion I follows.

Question 18

Inference about hill stations and amenities: from 'All hill stations have a sun-set point' and 'X is a hill station', determine which conclusions follow (X has a sun-set point; non–hill stations lack sun-set points)

Accepted Answer

Given data Premise 1: All hill stations ⟶ have a sun-set point. Premise 2: X is a hill station. Conclusions: I: X has a sun-set point. II: Places other than hill stations do not have sun-set points. Concept/Approach (why this method) Apply universal instantiation for X; avoid adding unstated exclusivity ('only hill stations have...'). Step-by-Step calculation / logic 1) From Premise 1, any hill station has a sun-set point; since X is one, X has it ⇒ I true.2) Premise 1 does not say non–hill stations lack it; II is an unwarranted converse ⇒ false. Verification/Alternative Counterexample to II: A non–hill station city could also have a sun-set viewpoint; premises don’t forbid it. Common pitfalls Reading 'All hill stations have P' as 'Only hill stations have P'. Final Answer Only conclusion I follows.

Question 19

Set-relation reasoning with overlap: given 'Some dreams are nights' and 'Some nights are days', decide which conclusions necessarily follow (All days are either nights or dreams; Some days are nights)

Accepted Answer

Given data Premise 1: Some Dreams ∩ Nights ≠ ∅. Premise 2: Some Nights ∩ Days ≠ ∅. Conclusions: I: All Days ⊆ (Nights ∪ Dreams). II: Some Days ∩ Nights ≠ ∅. Concept/Approach (why this method) Particular ('some') statements guarantee existence of overlap; they do not justify sweeping universals about entire sets. Step-by-Step calculation / logic 1) From Premise 2, there exists at least one element that is both Day and Night ⇒ II is necessarily true.2) Nothing links all Days to Nights or Dreams ⇒ I is not compelled and is overgeneralization. Verification/Alternative Construct sets where only a small portion of Days overlap Nights; I fails while II holds. Common pitfalls Treating 'some' as 'all'. Final Answer Only conclusion II follows.

Question 20

Abstract syllogism trap: 'All jungles are tigers' and 'Some tigers are horses' — evaluate whether any conclusion about horses and jungles is logically necessary

Accepted Answer

Given data Premise 1: Jungles ⊆ Tigers. Premise 2: Some Tigers are Horses. Conclusions: I: Some Horses are Jungles. II: No Horse is Jungle. Concept/Approach (why this method) Premise 2 tells us only that the Horses set intersects Tigers somewhere; it does not say that it intersects the particular subset 'Jungles'. Either overlap or disjointness with 'Jungles' is possible. Step-by-Step calculation / logic 1) If the Horses subset inside Tigers coincides with Jungles, I could be true; if it sits outside Jungles, I is false.2) Because both I and its negation are possible under the premises, neither I nor II is a necessary conclusion. Verification/Alternative Two models consistent with premises: (A) Horses ∩ Jungles ≠ ∅ (I true); (B) Horses ∩ Jungles = ∅ (II true). Since truth varies by model, neither follows. Common pitfalls Forcing a relationship between two subsets of the same superset without information. Final Answer Neither I nor II follows.

Logical Deduction Questions