If the first day of a year (other than the leap year) was Friday, then which one of the following was the last day of that year ?

In a non-leap year (ordinary year), there are 365 days. To find the day of the week, we look at the number of "odd days" (remainder after dividing by 7).

• 365 days = 52 weeks + 1 day.
• Since there are exactly 52 weeks and 1 extra day, the year ends on the same day of the week it started.

Mathematically, if the 1^st day of the year is Friday, then after 364 days (which is exactly 52 weeks), we reach the 365^th day. Because 364 is perfectly divisible by 7, the 365^th day (December 31) will be the same as the 1^st day (January 1).

Therefore, if the first day of a non-leap year is Friday, the last day of that year is also Friday. (Note: In a leap year of 366 days, the last day would be one day after the first day, i.e., Saturday).