Results 1 to 2 of 2

Math Help - Combinations/Probability...please check my work

  1. #1
    Member
    Joined
    Jan 2010
    Posts
    104

    Combinations/Probability...please check my work

    A) In a board game, there are tiles with letters on one side. There are 56 with consonants and 42 with vowels. A player chooses 7 tiles to start. What is the probability of choosing 4 consonants and 3 vowels?

    Is it ((56C4)(42C3))/(98C7)?

    B) You arrange five books (A, B, C, D, E) on a shelf. What is the probability that book E is last?
    I know intuitively it is 1/5, but I need to use combinations. How do I do so?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,962
    Thanks
    1784
    Awards
    1

    Wink

    Quote Originally Posted by twittytwitter View Post
    A) In a board game, there are tiles with letters on one side. There are 56 with consonants and 42 with vowels. A player chooses 7 tiles to start. What is the probability of choosing 4 consonants and 3 vowels? Is it ((56C4)(42C3))/(98C7)

    B) You arrange five books (A, B, C, D, E) on a shelf. What is the probability that book E is last?
    I know intuitively it is 1/5, but I need to use combinations. How do I do so?
    Your answer to part A is correct.

    For part B. You need permutations.
    There are 5! ways to arrange the five books.
    E will be the last book in 4! of those arrangements.
    So your intuition is correct.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 4
    Last Post: March 12th 2011, 05:05 AM
  2. Replies: 1
    Last Post: July 26th 2010, 09:34 PM
  3. Probability Please check my work!
    Posted in the Discrete Math Forum
    Replies: 4
    Last Post: July 23rd 2009, 05:57 PM
  4. IRV Probability Question - check my work?
    Posted in the Advanced Statistics Forum
    Replies: 4
    Last Post: February 24th 2009, 12:59 AM
  5. Please check my probability work guys...
    Posted in the Advanced Statistics Forum
    Replies: 5
    Last Post: March 10th 2008, 12:01 PM

Search Tags


/mathhelpforum @mathhelpforum