The calendar obviously has an integral number of years and months in 400 years. If it has an integral number of weeks, then it will repeat itself after that time. The rules of the calendar eliminate a leap year in 3 out of the four century years, so there are 97 leap years in 400 years. The number of excess days of the week in 400 years can be found by ...
(303·365) mod 7 + (97·366) mod 7 = (2·1 + 6·2) mod 7 = 14 mod 7 = 0
Thus, there are also an integral number of weeks in 400 years.
The first day of the week is the same at the start of every 400-year interval, so the calendar repeats every 400 years.
Answer:
2(n+1)+2
You start with two greens and two columns of two orange squares while adding two orange squares each time. So, the bolded part is the green squares that stay the same. The 2(n+1) represents the two orange columns that increase by one block on each side per image.
Answer:
211
Step-by-step explanation:
2 * 7 = 14 (the number of tiles for each row) 23 - 14 = 9 (the number of tiles subtracted from how many tiles that are taken away) 9 tiles are in the seventh row.
