Results 1 to 4 of 4
Like Tree1Thanks
  • 1 Post By Plato

Math Help - Probability question

  1. #1
    Junior Member
    Joined
    Aug 2012
    From
    The Earth
    Posts
    71
    Thanks
    1

    Probability question

    A box contains 10 digits in it, which is 0,1,2,3,4,5,6,7,8,9. When a digit is drawn out, a replacement is placed into the box. A 3-digit number is drawn.
    1. The probability of all the drawn digit are the same.
    2. The probability of two same digits is drawn.
    3. The probability of all the digits drawn are different.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,708
    Thanks
    1638
    Awards
    1

    Re: Probability question

    Quote Originally Posted by alexander9408 View Post
    A box contains 10 digits in it, which is 0,1,2,3,4,5,6,7,8,9. When a digit is drawn out, a replacement is placed into the box. A 3-digit number is drawn.
    1. The probability of all the drawn digit are the same.
    2. The probability of two same digits is drawn.
    3. The probability of all the digits drawn are different.
    There are 10^3 possible numbers: 000,~001\text{ to }998,~999.

    1. How many of those have all digits the same? Now divide.

    2. How many of those have two digits the same? Now divide.

    Post your answers.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Aug 2012
    From
    The Earth
    Posts
    71
    Thanks
    1

    Re: Probability question

    1. 10/1000=0.01
    2. How can I get the numbers with 2 same digit? Did I needs to list out all the numbers from 000 to 999 and picks the numbers that have 2 same digit?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,708
    Thanks
    1638
    Awards
    1

    Re: Probability question

    Quote Originally Posted by alexander9408 View Post
    1. 10/1000=0.01
    2. How can I get the numbers with 2 same digit? Did I needs to list out all the numbers from 000 to 999 and picks the numbers that have 2 same digit?
    There are ten ways to select the doubled digit; nine ways to select the single digit; three ways to arrange those digits.
    Thanks from alexander9408
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: May 6th 2013, 10:29 AM
  2. Replies: 0
    Last Post: May 5th 2013, 07:32 PM
  3. Replies: 5
    Last Post: February 10th 2013, 02:11 PM
  4. Probability question involving (A given B type question )
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: November 9th 2009, 09:08 AM
  5. A probability question and an Expectations question
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: January 29th 2006, 06:13 PM

Search Tags


/mathhelpforum @mathhelpforum