Deductive and Inductive Reasoning Questions and Answers

Answer: C

The key gives a large circle, with two separate smaller circles inside it.

Kabaddi players and football players are both players, so both smaller sets must lie inside the circle for players. Of the four diagrams, only this one places both inside the large circle; it shows the two groups as separate, which is the reading the key adopts.

Three concentric circles would mean every football player is a kabaddi player (or the reverse). A circle outside the large one would mean some kabaddi or football players are not players at all. Three circles in a row, each overlapping the next, would mean some kabaddi players are not players. All three contradict the fact that both groups are players.

Answer: B

The correct diagram is (B): two overlapping circles inside a large circle.

Sisters and mothers are both women, so both circles lie inside the circle for women. The two groups overlap, because some women are both sisters and mothers, some sisters are not mothers, and some mothers are not sisters (a woman with no siblings who has children).

(A) keeps sisters and mothers apart, as if no woman could be both. (C) nests one group wholly inside the other, as if every mother were a sister. (D) puts one group outside the women altogether, which is impossible since every sister and every mother is a woman.

Answer: D

Neither conclusion 1 nor conclusion 2 follows.

Conclusion 1, 'Some politicians are not aggressive', cannot be drawn from 'Some politicians are aggressive'. 'Some are' does not tell us that others are not; it is possible that every politician is aggressive.

Conclusion 2, 'Some players are politicians', does not follow either. Players and politicians are both linked only to the class of aggressive people. All players lie inside that class and some politicians lie inside it too, but the two groups may sit in different parts of it without overlapping. Since neither conclusion is certain, the options '1 only', '2 only' and '1 and 2 both' are all wrong.

Answer: B

This is an example of a fallacy.

In each case the energy comes from Bournvita (printed 'Bornvita'), Complan or milk, not from the water in which they are taken. Concluding that water gives energy because it is present in every case attributes the effect to the wrong common factor. It is a faulty inference, a fallacy of false cause (and, in Indian logic, of a wrong vyapti).

An invariable relation (vyapti) would need water to give energy in every case on its own, which it does not. Perception and comparison (upamana) are other means of knowledge, not descriptions of this flawed argument.

Answer: A

The valid conclusions are 1 and 2 only.

From 'All birds are white', the particular 'Some birds are white' follows (conclusion 1, by subalternation). From 'All parrots are birds' and 'All birds are white', the syllogism gives 'All parrots are white', so 'Some parrots are white' follows too (conclusion 2).

Conclusion 3 contradicts that result, since the parrots must be white, not green. Conclusion 4 contradicts statement I directly. So every option including 3 or 4 is wrong.

Answer: C

The correct diagram is three circles, each overlapping both of the others, with a region common to all three.

Some entrepreneurs are married and some are not; some entrepreneurs are women and some are not; some women are married and some are not; and some people are all three, married women entrepreneurs. Every pair overlaps and all three share a region.

Concentric circles would make one class wholly inside another, the chain would deny any overlap between two of the classes, and a separate circle would make one class share nothing with the others.

Answer: B

The valid conclusion is 2 only.

'All political leaders are intelligent' implies that some political leaders are intelligent (a universal statement implies the particular, taking the class to have members), so Conclusion 2 follows.

'Some tigers are goats' tells us nothing about whether any goats lie outside the tigers; it is possible that all goats are tigers. So 'Some goats are not tigers' does not follow, and every option including Conclusion 1 is wrong.

Answer: D

The answer is Neither 1 nor 2.

Conclusion 1, 'Some tax payers are not honest', directly contradicts Statement I, 'All tax payers are honest', so it cannot follow.

Conclusion 2, 'Some students are tax payers', does not follow either. Both statements only say that tax payers and students lie inside the set of honest people; they could be completely separate groups within it. Two 'All ... are honest' statements say nothing about how tax payers and students overlap. So neither conclusion is valid.

Answer: A

The proposition 'some men are not honest' is an O proposition (particular negative). Its contradictory is the A proposition 'all men are honest', since the two always have opposite truth values. 'Some men are honest' is its subcontrary (the I proposition), which can be true together with it. 'No men are honest' (E) implies it, so it is a stronger statement and not its contradictory. So the contradicting statement is 'all men are honest', and 'all of the above' is wrong.

Answer: D

A stipulative definition assigns a meaning to a term by decision or agreement, introducing a new term or giving an old one a new sense. Because it is a proposal or a rule for use, it is not a claim about what the word already means, so it cannot be true or false. Only reportive (lexical) definitions, which describe actual usage, can be true or false. The answer is neither true nor false. For example 'let the word terrain mean flat land' is a stipulation, and we cannot say it is true or false, only that it is convenient or not.