Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Probability question (Counting)

  1. Jan 25, 2006 #1

    jtm

    User Avatar

    imagine a 8 letter word, how many possibilities are there to arrange letters in the alphabet (26) that start with BO(in that order) OR end with BO (in that order), if letters can be repeated?

    This is my work:

    1 * 1 * 26 * 26 * 26 * 26 * 26 * 26 = 26^6 +

    26 * 26 * 26 * 26 * 26 * 26 * 1 * 1 = 26^6

    BUT I'm not sure what the intersection is because:

    do we subtract 1 or 26^4?

    my logic from 26^4 is coming from BOLLLLBO <-- where L is any letter

    Thank you!
     
  2. jcsd
  3. Jan 25, 2006 #2

    StatusX

    User Avatar
    Homework Helper

    Your logic sounds right.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook