Results 1 to 4 of 4

Math Help - an investment

  1. #1
    Member
    Joined
    Sep 2009
    Posts
    106

    an investment

    an investment yields an annual interest of $1500. If $500 more is invested and the rate is 2% less, the annual interest is $1300. What is the amount of investment and the rate of interest?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28
    Sounds like a job for some simultaneous equations.

    Given A is the initial amount invested, r is the rate then

    Maybe use

    (1+r)A= 1500+A ...(1)

    and

    (A+500)(1+(r-2))=1300+(A+500) ...(2)

    Leaves you with some algebra.

    I may be over complicating this one, it is early morning here!
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,676
    Thanks
    608
    Hello, aeroflix!

    An investment yields an annual interest of $1500.
    If $500 more is invested and the rate is 2% less, the annual interest is $1300.
    What is the amount of investment and the rate of interest?

    Let x = amount invested.
    Let r = rate of interest.


    We are told that x dollars at r percent yields $1500.

    . . Equation: . rx \:=\:1500


    We are told that (x+500) dollars at (r-0.02) percent yields $1300.

    . . Equation: . (x+500)(r-0.02) \:=\:1300


    Now solve the system of equations.


    You will get a quadratic equation
    and must discard one of the roots.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member
    Joined
    Sep 2009
    Posts
    106
    thanks
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. investment problem
    Posted in the Business Math Forum
    Replies: 4
    Last Post: December 4th 2011, 05:52 PM
  2. investment
    Posted in the Algebra Forum
    Replies: 3
    Last Post: August 12th 2010, 10:42 PM
  3. Investment
    Posted in the Business Math Forum
    Replies: 10
    Last Post: August 26th 2009, 10:05 AM
  4. investment
    Posted in the Business Math Forum
    Replies: 3
    Last Post: November 7th 2007, 07:27 PM
  5. X investment
    Posted in the Business Math Forum
    Replies: 4
    Last Post: August 21st 2007, 11:04 PM

Search Tags


/mathhelpforum @mathhelpforum