Which 2 months in a year has same Calendar
Duration: 15 min
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AI Summary
An AI-generated summary of this video lecture.
This educational video is a comprehensive lecture on calendar-based problems, a common topic in competitive exams. The instructor, Yash Jain Sir, systematically explains the concept of 'same calendar' months, which refers to months that start and end on the same day of the week. The lesson begins with a foundational problem: determining the day of the week for June 25, 2015, given that October 1, 2010, was a Monday. The core of the video is a series of practice questions from various IT companies like IBM, TCS, Infosys, and Wipro. The instructor demonstrates a methodical approach to solve these problems by calculating the number of odd days between months. For instance, he explains that two months have the same calendar if the total number of days between them is a multiple of 7. He provides a list of month pairs that share the same calendar, such as January and October, February, March, and November, April and July, and September and December. The video also covers related concepts, including the number of months with 31 days that start and end on the same day, and the number of unique months in a year. The presentation uses a digital blackboard with handwritten notes and diagrams to illustrate the calculations and concepts clearly.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a title slide featuring a calendar and the word 'CALENDAR'. It then transitions to a lecture by Yash Jain Sir, who introduces a problem: '1st October 2010 → Monday, 25th June 2015 → ???'. The slide is titled 'Four Categories' and lists different types of date-related problems. The instructor explains that the video will cover important questions asked in IT companies, with a quiz at the end.
2:00 – 5:00 02:00-05:00
The instructor continues to explain the problem of finding the day of the week for June 25, 2015. He introduces the concept of 'same calendar' months, where two months have the same starting and ending days. He presents a list of month pairs that share the same calendar, such as January-October, February-March-November, April-July, and September-December. The slide shows a list of four categories of problems, and the instructor begins to discuss the first two categories: 'Month and Year Same, Date Different' and 'Date and Month Same, Year Different'.
5:00 – 10:00 05:00-10:00
The video focuses on a question from IBM: 'Which two months in a year have the same calendar?'. The options are A) June, October, B) April, November, C) April, July, D) April, July, December. The instructor explains that the correct answer is A) June, October, as they have the same calendar. He demonstrates the calculation by showing the number of odd days between the months. He also explains that the list of month pairs with the same calendar is: January-October, February-March-November, April-July, and September-December.
10:00 – 14:51 10:00-14:51
The video presents a series of practice questions. The first is from TCS: 'For a non-leap year, how many months have 31 days and start and end on the same day?'. The instructor explains that the answer is 4, corresponding to the pairs January-October, February-March-November, April-July, and September-December. The next question is from Infosys: 'For a non-leap year, how many months have 30 days and start and end on the same day?'. The instructor explains that the answer is 4, with the same pairs. The final question is from Wipro: 'How many unique months does an ordinary year have?'. The instructor explains that the answer is 3, as some months are duplicates. The video concludes with a 'Thanks for Watching' screen.
The video provides a structured and practical guide to solving calendar problems. It begins with a foundational example to establish the concept of 'same calendar' months, then systematically applies this concept to a series of real-world exam questions. The key method demonstrated is calculating the number of odd days between months to determine if they share the same calendar. The instructor uses a consistent framework of listing the month pairs that have the same calendar, which is a powerful tool for quickly solving these types of problems. The progression from basic concepts to complex, multi-part questions ensures a comprehensive understanding of the topic.