Discussion
If today is Monday, then which day will it exactly be on 79th day?
Answer: A
The key gives Monday.
Days repeat every 7. Reading the question, as the key does, as the day that comes \(7^{9}\) days after today: \(7^{9}\) is an exact multiple of 7, so that many days is a whole number of weeks and the weekday is unchanged.
\[ 7^{9} \equiv 0 \pmod 7 \]
The point of the question is that any power of 7 leaves remainder 0 on division by 7, so no counting is needed. Wednesday, Saturday and Tuesday would each need a remainder of 2, 5 or 1 days.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development