Question

Сколько в 21 столетии лет,в которых 1 января будет тем же днём недели,что и 31 декабря,если известно,что 2100 год не считается высокосным,а 2000 год относится к 20 столетию? А-74 раза,Б-75 раз,В-76 раз, Г-80 разПомогите плиз

Answer 1

 зная что высокосный год бывает раз в четаре годаполучаем                                                                                 100/4-1=24

Answer 2

Calculation of the Number of Years in the 21st Century with the Same Day of the Week for January 1st and December 31st

To determine the number of years in the 21st century where January 1st and December 31st fall on the same day of the week, we need to consider the leap years and the century change from the 20th to the 21st century.

According to the information provided, the year 2100 is not considered a leap year, and the year 2000 is part of the 20th century.

To calculate the number of years, we can follow these steps:

1. Determine the number of years in the 21st century: 2001 to 2100. 2. Subtract the number of leap years in this period. 3. Subtract the number of years that have a century change from the 20th to the 21st century.

Let's calculate each step:

1. Number of years in the 21st century: 2100 - 2001 + 1 = 100 years.

2. Number of leap years in the 21st century: - Leap years occur every 4 years, except for years divisible by 100, unless they are divisible by 400. - The first leap year in the 21st century is 2004, and the last leap year is 2096. - The number of leap years in this period is (2096 - 2004) / 4 + 1 = 24 leap years.

3. Number of years with a century change from the 20th to the 21st century: - The last year of the 20th century is 2000. - The first year of the 21st century is 2001. - The number of years with a century change is 2001 - 2000 = 1 year.

Now, let's calculate the final result:

Number of years with January 1st and December 31st falling on the same day of the week in the 21st century = 100 years - 24 leap years - 1 year = 75 years.

Therefore, the correct answer is Б-75 раз.

Please let me know if there is anything else I can help you with!