Tagged with day number …

#math trivia #244 solution

#math trivia for #September1: #244 is the integer after (8/12)*365. Which other months start on the “right” day-number for the month? — Burt Kaliski Jr. (@modulomathy) September 2, 2013 The “right” day-number for month number M to start on, based on the first sentence, is apparently the integer after ((M-1)/12)*365.  The logic is that each … Continue reading →

#math trivia #171 solution

#math trivia for #June19: #171 is one of five palindrome day-numbers (same forward and reverse) divisible by 9. What are the others? — Burt Kaliski Jr. (@modulomathy) June 20, 2012 The sum of the digits of a number divisible by 9 is itself divisible by 9; this follows from the fact that powers of 10 … Continue reading →