Today is Monday in a calendar based reasoning question. After exactly 61 days from today, which day of the week will it be?

Introduction / Context:
This problem checks your ability to handle modular arithmetic in the context of calendars. Instead of working with specific dates, it uses a relative description: starting from Monday, you must determine the weekday after a certain number of days. Such questions appear frequently in aptitude tests and can be solved quickly using remainders when dividing by 7.

Given Data / Assumptions:
- Today is Monday.
- We are asked for the weekday after 61 days.
- A standard week has 7 days.
- We assume no changes to the calendar system (no skipped days or special rules).

Concept / Approach:
The key idea is that weekdays repeat every 7 days. Therefore, only the remainder when the number of elapsed days is divided by 7 matters. If the remainder is r, then we move forward by r steps from the starting weekday. This allows us to avoid counting all 61 days one by one.

Step-by-Step Solution:
Step 1: Note that the length of a week is 7 days, so we compute 61 modulo 7.Step 2: Divide 61 by 7: 7 * 8 = 56, and 61 - 56 = 5.Step 3: Therefore, 61 days correspond to 8 complete weeks plus a remainder of 5 days.Step 4: Complete weeks bring us back to the same weekday, so only the remainder of 5 days affects the weekday name.Step 5: Starting from Monday, count forward 5 days: Monday (0), Tuesday (1), Wednesday (2), Thursday (3), Friday (4), Saturday (5).Step 6: After moving 5 days ahead from Monday, we arrive at Saturday.

Verification / Alternative check:
You can verify by shorter steps. After 7 days it is again Monday, after 14 days again Monday, and so on. After 56 days (which is 7 * 8) it is still Monday. Then you simply count 5 more days: Tuesday, Wednesday, Thursday, Friday, Saturday. This quick mental confirmation reinforces that Saturday is correct.

Why Other Options Are Wrong:
Sunday, Monday, Tuesday and Wednesday correspond to different remainders. For example, Sunday would match a remainder of 6 days, Tuesday would match a remainder of 1 day, and so on. None of these align with the calculated remainder of 5 when 61 is divided by 7.

Common Pitfalls:
Learners often forget to take the remainder and instead count full weeks incorrectly, or they miscount the steps forward from the starting day. Another error is to treat the starting day as step 1 instead of step 0. To avoid confusion, treat the starting day as position 0 and then count the remainder days forward carefully.

Final Answer:
After 61 days from Monday, the day of the week will be Saturday.