Statement & Assumption — “Travelling by trains rather than cabs is more convenient and economical in Paris.” Which assumptions are implicit? I. Paris is an expensive city. II. Train services in Paris are reasonably good.

Introduction / Context:
The statement compares modes of transport in Paris and judges trains superior on convenience and cost. We must identify necessary premises.

Given Data / Assumptions:

• A comparison is drawn between trains and cabs.
• “More convenient and economical” implies acceptable service quality and pricing.

Concept / Approach:
Assumption II is required: for trains to be more convenient, train services must be reasonably good (frequency, coverage, reliability). Assumption I (Paris is expensive) is not required; trains can be cheaper than cabs regardless of the city’s absolute price level.

Step-by-Step Solution:
Affirm II: Quality of train services underpins convenience.Reject I: Relative cost advantage does not depend on overall city expense.

Why Other Options Are Wrong:
Including I adds a nonessential macroeconomic claim.

Final Answer:
if only Assumption II is implicit