Results 1 to 2 of 2
Like Tree1Thanks
  • 1 Post By Goku

Math Help - A set of n positive numbers. Find the largest possible value of n.

  1. #1
    Newbie
    Joined
    May 2012
    From
    Ohio
    Posts
    7

    A set of n positive numbers. Find the largest possible value of n.

    Sorry I'm new to the forums and I'm not sure if this belongs here but some help on this one would be greatly appreciated. Thanks in advance.

    The average of some set of n positive numbers is 60. After removing one of the numbers, the average of the remaining numbers is 70. What is the largest possible value of n?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member Goku's Avatar
    Joined
    Mar 2011
    From
    South Africa
    Posts
    84
    Thanks
    10

    Re: A set of n positive numbers. Find the largest possible value of n.

    We have:

    \frac{x_1+x_2+... +x_{n-1}+x_{n}}{n}=60 [1]

    And

    \frac{x_1+x_2+... +x_{n-1}}{n-1}=70

    x_1+x_2+... +x_{n-1}=70(n-1)

    Note that I removed x_n you could remove some x_i

    now substitute in [1]:
    you get

    70(n-1) + x_n = 60n
    x_n = 70 -10n

    so n < 7....
    Thanks from wannabebrainiac
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: April 15th 2010, 07:16 PM
  2. determining the largest set D of real numbers
    Posted in the Algebra Forum
    Replies: 2
    Last Post: March 12th 2009, 02:31 AM
  3. determining the largest set D of real numbers
    Posted in the Algebra Forum
    Replies: 6
    Last Post: March 11th 2009, 10:38 PM
  4. Replies: 2
    Last Post: February 22nd 2009, 03:49 PM
  5. Replies: 1
    Last Post: October 15th 2008, 12:54 PM

Search Tags


/mathhelpforum @mathhelpforum