It's Friday the 13th today

Lola

But my colleague reminded me the bright side.......


IT IS PAY DAY!

In fact, every Friday the 13th is a pay day for those whose normal pay day is 15th every  month.

Besides, the sun finally came out after two wet weeks!
Other than the morning tea invitation in the calendar, there is no other meetings.
Going out for lunch with girlfriends.
Looking forward to an early mark and a busy shopping weekend.

So today should be a good day.e

Hope you have a good day too.

[ 本帖最后由 Lola 于 2008-6-13 09:25 编辑 ]

degra

TODAY IS BLACK FRIDAY!!!

WTFAUS

BLACK FRIDAY?  

hmm its not even a pay day for me.
maybe I just sit and do nothing today just in case anything bad happens...

xingbu

it's our pay day as well:)
i've already arranged everything yesterday.

carpediem

Black Friday?!

degra

Question， what is the chance of having a black friday in a year?

bffbffbff

today is my pay day too... and without suprise, the amount remains unchanged ,
pathetic , isn't it?

bffbffbff

less than 1/7

阿Ka

原帖由 gandu 于 2008-6-13 09:38 发表
Question， what is the chance of having a black friday in a year?

around 0.23

degra

are you sure?, it should be higher

bffbffbff

without  having a mathematic analysis,  I think if every months is equally long, then there will be 1/7 chance for 13th of month to be Friday...

does anyone agree?

阿Ka

原帖由 gandu 于 2008-6-13 09:43 发表
are you sure?, it should be higher

one year: 12 13th's, 51-53 fridays,
so
p = 12/52

degra

we have 12 / 365.25  chance of having a 13th and 1/7 chance of having a friday, then 12/365.25/7 chance of have a black friday?

[ 本帖最后由 gandu 于 2008-6-13 09:54 编辑 ]

阿Ka

原帖由 gandu 于 2008-6-13 09:52 发表
we have 12 / 365.25  chance of having a 13th and 1/7 chance of having a friday, then 12/365.25/7 chance of have a black friday?

I 服了 u!!! 没分加了

bffbffbff

原帖由 gandu 于 2008-6-13 09:52 发表
we have 12 / 365.25  chance of having a 13th and 1/7 chance of having a friday, then 12/365.25/7 chance of have a black friday?

well, It is right if the question is "chance of having a black friday in a year"?

and

if the question is  "what is the chance for every 13th to be black friday", then the answer will be  1/7.

if the question is "what is the chance for every friday to be black friday", then the answer will be 12 / 365.25



[ 本帖最后由 bffbffbff 于 2008-6-13 10:11 编辑 ]

benben

我今天也发工资了，高兴

我爱猫

N年前看过一系列的恐怖片，从此就记得Friday, the 13th..

汗， 刚看，了一下，对这Friday the 13th这种恐惧感有个专有名词:

"paraskavedekatriaphobia"

perfume

恩,今天要考试,希望顺利...

光子

今天CPA出成绩，希望不要太差啊

carpediem

原帖由 perfume 于 2008-6-13 10:31 发表
恩,今天要考试,希望顺利...

Good Luck!

widelink

原帖由 bffbffbff 于 2008-6-13 09:48 发表
without  having a mathematic analysis,  I think if every months is equally long, then there will be 1/7 chance for 13th of month to be Friday...

does anyone agree?

Actually each day of month or year has the same chance as 1/7 to Monday , Tuesday ,... or Sunday unless there would not be seven days in one week .   

bffbffbff

see 15# for correct version

阿Ka

原帖由 我爱猫 于 2008-6-13 10:16 发表
N年前看过一系列的恐怖片，从此就记得Friday, the 13th..

汗， 刚看，了一下，对这Friday the 13th这种恐惧感有个专有名词:

"paraskavedekatriaphobia"

令偶恐惧的是你居然记得这个单词:o

Lola

wow, both discussions are so mentally challenging.

I am mentally disabled today.

big_beast

一年有多少机会遇上黑色星期五的问题，俺觉得不是排列组合的问题，而仅仅是一个排数的问题
首先，一个月不是固定的30天，其次，一年也不是固定的365天……所以，还是查日历比较简单……

maribel

原帖由 我爱猫 于 2008-6-13 10:16 发表
N年前看过一系列的恐怖片，从此就记得Friday, the 13th..

汗， 刚看，了一下，对这Friday the 13th这种恐惧感有个专有名词:

"paraskavedekatriaphobia"

我好像也看过这部恐怖片。是不是讲一对去CAMPING的年轻人的？凶手是个老太太？

maribel

原帖由 我爱猫 于 2008-6-13 10:16 发表
N年前看过一系列的恐怖片，从此就记得Friday, the 13th..

汗， 刚看，了一下，对这Friday the 13th这种恐惧感有个专有名词:

"paraskavedekatriaphobia"

猫猫请另外知道一下这个单词的发音

好像所有和PHOBIA有关的单词都爆恐怖的长。。。。。

degra

原帖由 阿狗 于 2008-6-13 10:58 发表


令偶恐惧的是你居然记得这个单词:o

也令我恐惧。.