1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Probability that a Year with 53 Sundays is a Leap Year?

  1. Jan 28, 2015 #1


    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data
    A year has 53 Sundays. What is the conditional probability that it is a leap year.

    2. Relevant equations
    None that I can think of.

    3. The attempt at a solution
    I tried by knowing that a leap year has 366 days. Next we can note that the remaining 2 days could be sunday and monday, monday and tuesday, .... and saturday and sunday. Sunday appears 2 out of 7 times, so the answer I got was 2/7. Is that correct or did I do something wrong?
  2. jcsd
  3. Jan 29, 2015 #2


    User Avatar
    Homework Helper

    You forgot the conditional part.
    If A = 53 Sundays and B= Leap Year, you found p(A|B). You want p(B|A).
    You still need to know the probability of 53 Sundays on a non-leap year.
  4. Jan 29, 2015 #3


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    To answer this you need to use knowledge of how often leap years occur. The questioner probably expects you to use 1/4, but strictly speaking it's (1/4-1/100+1/400).
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted