Difficulty: Easy
Correct Answer: Only I and III are implicit
Explanation:
Introduction / Context:The action is to book in May for a July trip. We identify which background beliefs must hold for this plan to be sensible.
Given Data / Assumptions:
Concept / Approach:Advance booking implies (a) such booking is allowed around that time horizon and (b) a reasonable chance of getting a seat in the intended class. The number of trains is not crucial.
Step-by-Step Solution:
1) I is necessary: if reservations are not opened two months early, booking in May for July would not be possible.2) II is unnecessary: even a single train could be the target of the reservation.3) III is necessary in a practical sense: deciding to book assumes some availability; otherwise the plan would be futile.Verification / Alternative check:Negate I or III: the plan loses feasibility. Negate II: the plan still works with one train.
Why Other Options Are Wrong:
Common Pitfalls:Confusing “decision to book” with “guaranteed confirmation.” The assumption is about reasonable possibility, not certainty.
Final Answer:Only I and III are implicit
Discussion & Comments