Question

Probability question

Answer 1

@jhonyy9

Answer 2

This blog post answers the question I think

http://blogs.mathworks.com/cleve/2012/07/09/friday-the-13th/

Answer 3

hmm strange, the link works for me

try another browser maybe?

Answer 4

anyways the blog post has a ton of math and matlab on it

the conclusion the author reaches is that the probability of having a friday the 13th is roughly 0.143333 while 1/7 = 0.142857 approx

so it's close to 1/7, but not quite

Answer 5

so me working this site too by google chrome

Answer 6

okay opened it with proxy,

hey but the answer given is \(\dfrac{1}{12}\times \dfrac{1}{7}=\dfrac{1}{84}\)

Answer 7

hmm I guess you could see it as the chances of picking any given month is 1/12
the chances of having the 13th land on friday is 1/7 (since it's equally possible for it to land on any day of the week)

so 1/12*1/7 = 1/84

Answer 8

which answer is correct ?

Answer 9

I'm not sure, but it seems like the matlab post has more merit because the author generated calendar data and used it to get a more realistic answer

the 1/84 seems to be based on more simpler (unrealistic) assumptions

if your teacher said the answer is 1/84, then it sounds like you're going with those assumptions

Answer 10

thnx

Answer 11

np