If it was a Monday on 1 January 2018, what was the day of the week on 31 December 2018? |
Tuesday Monday Saturday Thursday |
Monday |
\(\frac{Date + Month\;code + Century\;code + Century\;upper\;year + Quotient\;of\;\frac{upper\;year}{4}}{7}\) \(\frac{1 + 0 + 6 + 18 + 4}{7}\) = \(\frac{29}{7}\) = Remainder 1 so, remainder is 1 The day for Code 1 is monday. So, it is the same day which is given therefore, The day for 31 december 2018 was : \(\frac{Date + Month\;code + Century\;code + Century\;upper\;year + Quotient\;of\;\frac{upper\;year}{4}}{7}\) \(\frac{31 + 5 + 6 + 18 + 4}{7}\) = \(\frac{64}{7}\) = Remainder 1 The day for Code 1 is monday.
Note: Code for Mon – 1 Tues – 2 Wed – 3 Thurs – 4 Fri – 5 Sat – 6 Sun – 0 Code for Jan – 0 Apr – 6 July – 6 Oct – 0 Feb – 3 May – 1 Aug – 2 Nov – 3 Mar – 3 June – 4 Sep – 5 Dec – 5 Code for 1900 is 0 2000 is 6 2100 is 4 2200 is 2 2300 is 0 2400 is 6 2500 is 4 and Likewise |