Data Sufficiency — Day of the week for a visit: On which day did Hitesh visit the zoo? Statements: I. Hitesh did not visit on Tuesday or Thursday. II. Hitesh visited the zoo two days before his mother reached his house, and she arrived the day after Monday.

Introduction / Context:
We are to determine the exact weekday of Hitesh’s zoo visit. This is a timeline/offset problem framed in data sufficiency style, where specific offsets from a known reference day provide the unique answer.

Given Data / Assumptions:

• I: Excludes Tuesday and Thursday only.
• II: Mother arrives “the day after Monday,” i.e., Tuesday; Hitesh visited two days earlier.
• Days of the week follow the usual order: Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday.

Concept / Approach:
Translate the verbal offsets into exact days. If one statement pinpoints a unique day, it is sufficient by itself. If not, see whether combining statements is necessary.

Step-by-Step Solution:
From II: Mother arrives on Tuesday.Two days before Tuesday is Sunday (Tuesday − 2 → Monday − 1 → Sunday).Therefore, Hitesh visited the zoo on Sunday.Statement I alone only rules out two days and cannot fix a unique day.

Verification / Alternative check:
Cross-check with Statement I: Sunday is neither Tuesday nor Thursday, so there is no conflict. II alone already gives a unique answer, confirming sufficiency.

Why Other Options Are Wrong:

• I alone: Multiple days remain possible.
• Either / Both: II alone suffices; both are not required.
• Neither: Incorrect because II works.

Common Pitfalls:

• Miscalculating offsets (some mistakenly say Monday).
• Thinking “the day after Monday” could be ambiguous—it is Tuesday.

Final Answer:
II alone is sufficient while I alone is not sufficient