Difficulty: Easy
Correct Answer: (ii) and (iii)
Explanation:
Introduction / Context:We assess truth conditions of a disjunction: “Either CAT is tough or IIT JEE is easy.” In standard logic, “either … or …” is often read exclusively in puzzles, but the safe consistency check works for inclusive-or as well: the disjunction is true if at least one disjunct is true.
Given Data / Assumptions:
Concept / Approach:We must find a pair that does not contradict S. If we pick CAT easy (ii) and IIT JEE easy (iii), S remains satisfied because “IIT JEE easy” makes the disjunction true. Pairs that force both “CAT not tough” and “IIT JEE not easy” would contradict S.
Step-by-Step Solution:
1) Let C_t = “CAT tough”; J_e = “IIT JEE easy”.2) S asserts C_t OR J_e is true.3) Pair (ii)&(iii): “CAT easy” (which says nothing about toughness) and “IIT JEE easy” (J_e true). S is satisfied.4) Pair (ii)&(iv): “CAT easy” with “IIT tough” makes J_e false and does not guarantee C_t true; this can contradict S.5) Pair (iii)&(iv): asserts J_e true and J_e false simultaneously, a contradiction.Verification / Alternative check:If we treat “either … or …” as exclusive, (ii)&(iii) still keeps S true (since the clause only requires at least one to make the original sentence consistent; exclusivity is not enforced by the option pair itself).
Why Other Options Are Wrong:
Common Pitfalls:Assuming “CAT easy” implies “CAT not tough” with certainty. The prompt does not define “tough vs easy” as strict negations; even if treated as opposites, (iii) alone already satisfies S.
Final Answer:(ii) and (iii)
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