Results 1 to 3 of 3

Math Help - need urgent help

  1. #1
    Newbie
    Joined
    Jan 2009
    Posts
    19

    need urgent help

    Out of 200 students, 113 are on the honor roll or on a sports team. 80 students are on the honor roll, and 72 students are on a sports team. What is the probability that a student is chosen out of the 200 students who is on the honor roll and a sports team?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,686
    Thanks
    617
    Hello, IronMan21!

    Out of 200 students, 113 are on the honor roll or on a sports team.
    80 students are on the honor roll, and 72 students are on a sports team.
    What is the probability that a student is chosen out of the 200 students
    who is on the honor roll and a sports team?
    Are you familiar with this formula? . P(A \cup B) \;=\;P(A) + P(B) - P(A \cap B)


    Let . \begin{array}{ccc}H &=&\text{on Honor Roll} \\ S &=& \text{on Sports team}\end{array}


    We are told that: . P(H \cup S) = \tfrac{113}{200},\;P(H) = \tfrac{80}{200},\;P(S) = \tfrac{72}{200}


    \text{So we have: }\;\underbrace{P(H \cup S)}_{\frac{113}{200}} \;=\;\underbrace{P(H)}_{\frac{80}{200}} + \underbrace{P(S)}_{\frac{72}{200}} - P(H \cap S)


    Therefore: . P(H \cap S) \;=\;\tfrac{80}{200} + \tfrac{72}{200} - \tfrac{113}{200} \;=\;\boxed{\frac{39}{200}}

    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jan 2009
    Posts
    19
    thanks soroban!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Urgent!!!help with attempted questions - urgent
    Posted in the Statistics Forum
    Replies: 2
    Last Post: February 28th 2010, 12:29 AM
  2. I need urgent urgent hel with this parabola question
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: December 14th 2008, 04:48 PM
  3. Very urgent!
    Posted in the Algebra Forum
    Replies: 2
    Last Post: September 30th 2008, 01:01 PM
  4. Urgent HW help
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: March 14th 2008, 05:52 AM
  5. urgent HELP
    Posted in the Statistics Forum
    Replies: 1
    Last Post: July 12th 2007, 04:34 AM

Search Tags


/mathhelpforum @mathhelpforum