Show that the 13th of a month falls more frequently on Friday than on any other day.

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- Jun 4th 2006, 09:43 PMmalaygoel13th of a month
Show that the 13th of a month falls more frequently on Friday than on any other day.

- Jun 5th 2006, 12:07 AMCaptainBlackQuote:

Originally Posted by**malaygoel**

(the calendar has a 400 year cycle, and the frequencies need to be computed

over such a cycle - the intuitive equiprobability model for date/day distribution

is broken up by the leap/non-leap rules for years divisible by 100).

RonL - Jun 5th 2006, 06:54 AMmalaygoelQuote:

Originally Posted by**CaptainBlack**

- Jun 5th 2006, 07:43 AMCaptainBlackQuote:

Originally Posted by**malaygoel**

happens that for the 13th of the month the day with maximum frequency

is Friday.

RonL - Jun 5th 2006, 06:15 PMmalaygoelQuote:

Originally Posted by**CaptainBlack**

- Jun 5th 2006, 11:15 PMCaptainBlackQuote:

Originally Posted by**malaygoel**

Its a property of the Gregorian Calendar, IIRC doesn't happen in the Julian

Calendar.

RonL - Jun 17th 2006, 06:11 AMmalaygoelQuote:

Originally Posted by**CaptainBlack**

Then in the cycle of 400 years 13th of a month falls frequently on fridays.

If it would have been tuesday instead of monday, then 13th of a month would have fallen on saturdays(right????).

So it is just of trivial importance that we have January1 on such a day that 13th of a month falls on fridays. It has nothing to do with the probability. It is a fact that friday and 13 are good friends due to the day we assigned to January1 of 2001.

I hope you understand what I want to say. - Jun 17th 2006, 07:46 AMCaptainBlackQuote:

Originally Posted by**malaygoel**

would result in a different day having the greatest frequency of being

the 13th of the month.

RonL - Jun 17th 2006, 06:53 PMmalaygoelQuote:

Originally Posted by**CaptainBlack**