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 problem driving me crazy!

  1. Jun 18, 2010 #1
    So I'm going to the casino this weekend and it got me thinking about probability.

    If I have an n-sided die and roll it n times, what are the chances of me hitting a specific number, x?

    For example, if I flip a coin (n=2) twice, what are the chances of me hitting heads at least once?

    Answer (obvious for n=2): 1-.5^2 = .75

    It's obvious for most n's until they get large. I've simplified it to this equation:


    If I go back to n=2, we see that we arrive at the same answer of .75.

    My TI-89 can calculate up to an n of 100, which gives a value of .6340.

    I'm very interested in this value as n increases, though. Unfortunately I don't have access to math software that could solve the problem as a limit. How can I solve this, or more importantly... WHAT'S THE ANSWER?

    It's driving me crazy! My best guess is that it tends towards 1/2.

    Thanks for any help!
  2. jcsd
  3. Jun 18, 2010 #2
  4. Jun 19, 2010 #3


    User Avatar
    Science Advisor

    Yes the [itex]\left(\frac{n-1}{n}\right)^n[/itex] term aproaches [itex]1/e[/itex] so the limiting probability DyslexicHobo seeks is [itex]1 - 1/e[/itex], which is about 0.632
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Probability problem driving me crazy!
  1. Trig Driving me Insane (Replies: 11)