If the day before yesterday was Thursday, then on which day will Sunday fall relative to today?

Introduction / Context:
This is a basic day relationship problem that asks you to relate the current day to other days of the week based on a simple statement. The information given connects today to the day before yesterday, and from this we must infer the position of Sunday relative to today (whether it is today, tomorrow, or another day).

Given Data / Assumptions:

• The day before yesterday was Thursday.
• We must determine when Sunday occurs with respect to today.
• The weekly cycle is the standard Sunday to Saturday cycle repeating every 7 days.

Concept / Approach:
If the day before yesterday is known, we can find yesterday by moving one day forward, and today by moving one more day forward. Once today is identified, we can determine the relationship of Sunday to today by comparing positions in the weekly cycle. We need to express today in terms of a known weekday and then count forward to Sunday.

Step-by-Step Solution:
Step 1: Let us denote the current day as X. Step 2: The day before yesterday is two days before today. The statement says that this day is Thursday. Step 3: If X is today, then X - 2 days is Thursday. Step 4: Move forward from Thursday: one day after Thursday is Friday (yesterday), and two days after Thursday is Saturday (today). Step 5: Therefore, today is Saturday. Step 6: Sunday is the day immediately after Saturday. Step 7: So Sunday is tomorrow relative to today.

Verification / Alternative check:
We can verify by listing: Thursday (day before yesterday), Friday (yesterday), Saturday (today), Sunday (tomorrow). This matches the given condition and clearly shows Sunday is one day after Saturday, that is, on the next day after today.

Why Other Options Are Wrong:
Sunday cannot be today, because today has been identified as Saturday. Sunday is not the day after tomorrow in this scenario, because that would make today Friday, which contradicts the starting statement. The option none is not correct because a definite relationship exists, and Sunday is specifically tomorrow.

Common Pitfalls:
Some learners mistakenly shift the days in the wrong direction or misinterpret which day is "before yesterday". Remember that the day before yesterday is two days prior to today. Drawing a small timeline with three consecutive days marked can help avoid confusion about the relative positions of yesterday, today and tomorrow.

Final Answer:
Sunday will be tomorrow.