Results 1 to 4 of 4

Math Help - Probability problem help?

  1. #1
    Member
    Joined
    Jan 2009
    Posts
    197

    Exclamation Probability problem help?

    Question:

    There are 2 red balls and 4 yellow ones in a box.
    a) if a ball is drawn and replaced,and a second ball is drawn,what is the probability that the first ball is red and the second ball is yellow?
    b)What is the probability that the balls will be red and yellow combination in any order?

    Attempt:
    a) total no. of balls =6

    2P1+4P1 =6
     \frac{6}{6} =1

    b) 2C1+4C1=6
     \frac{6}{6} =1

    Are my answers correct because I doubt it ?

    thank you
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,605
    Thanks
    1574
    Awards
    1
    Quote Originally Posted by mj.alawami View Post
    There are 2 red balls and 4 yellow ones in a box.
    a) if a ball is drawn and replaced,and a second ball is drawn,what is the probability that the first ball is red and the second ball is yellow?
    b)What is the probability that the balls will be red and yellow combination in any order?
    a) \frac{2}{6} \cdot \frac{4}{6}

    b) 2\left(\frac{2}{6} \cdot \frac{4}{6}\right)

    Now WHY?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Jan 2009
    Posts
    197
    Quote Originally Posted by Plato View Post
    a) \frac{2}{6} \cdot \frac{4}{6}

    b) 2\left(\frac{2}{6} \cdot \frac{4}{6}\right)

    Now WHY?
    Shouldn't the first answer be related to permutation since they are in order and the second is combinations ?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,605
    Thanks
    1574
    Awards
    1
    Quote Originally Posted by mj.alawami View Post
    Shouldn't the first answer be related to permutation since they are in order and the second is combinations ?
    It has almost nothing to to do with permutations or combinations.

    a) There are two ways to pick a red ball out six. Then there are four ways to pick a yellow ball out six.

    b) is just twice a). Because we could have RY \text{ or }YR.

    Don't overthink this sort of question.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Probability problem
    Posted in the Statistics Forum
    Replies: 4
    Last Post: January 30th 2011, 07:16 PM
  2. Replies: 10
    Last Post: January 21st 2011, 11:47 AM
  3. Probability problem
    Posted in the Statistics Forum
    Replies: 2
    Last Post: October 30th 2009, 02:40 PM
  4. Replies: 0
    Last Post: October 8th 2009, 08:45 AM
  5. probability problem
    Posted in the Statistics Forum
    Replies: 2
    Last Post: August 16th 2008, 12:45 PM

Search Tags


/mathhelpforum @mathhelpforum