<p>divide 259 by 7 for the first one, since there are 7 days in a week, and the first day is already taken. take the remainder and add it to monday as in weekdays. since the remainder is 0, the answer is monday.</p>
<p>First one you can think about it like this:</p>
<p><em>1</em>rst day is monday, 2nd tuesday… 3, 4, 5, 6, 7, **8 is monday again, 9 tuesday so:</p>
<p>1+7w is the equation for everyday that’s a monday (you could set up 2 +7w as ever tueday), where ‘w’ pretty much stands for each week. You can then set up:</p>
<p>260 = 7d + 1 259 = 7d and you get no remainder so it must fall on a monday. If you get a remainder you can just logically count the offset, so if it was 262nd day, the remainder would be 2, so monday, tuesday, wednesday, etc.</p>