Results 1 to 3 of 3

Math Help - dimentions

  1. #1
    Newbie
    Joined
    Dec 2006
    Posts
    11

    dimentions

    the combined heights of two cubes are 11 metres and their combined volumes equal 407 cubic metres. Calculate the dimentions of each cube.

    workin out shown is greatly appreciated..
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by jaswinder View Post
    the combined heights of two cubes are 11 metres and their combined volumes equal 407 cubic metres. Calculate the dimentions of each cube.

    workin out shown is greatly appreciated..
    Already answered here

    RonL
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,689
    Thanks
    617
    Hello, jaswinder!

    The combined heights of two cubes are 11 m
    and their combined volumes equal 407 m.
    Calculate the dimentions of each cube.

    Let the heights of the cubes be x and y.

    We have: . x + y .= .11 . . y .= .11 - x .[1]

    . . . and: .x + y .= .407 .[2]


    Substitute [1] into [2]: .x + (11 - x) .= .407

    . . . . . . x + 1331 - 363x + 33x - x .= .407

    . . . . . . . . . . . . . .33x - 363x + 924 .= .0


    Divide by 33: . x - 11x + 28 .= .0

    . . . . Factor: . .(x - 4)(x - 7) .= .0

    And we have: .x .= .4, 7 . . y .= .7, 4


    Therefore, the heights of the cubes are 4 m and 7 m.

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Calculate Torus dimentions to align to a square grid.
    Posted in the Advanced Applied Math Forum
    Replies: 3
    Last Post: September 3rd 2010, 05:00 AM

Search Tags


/mathhelpforum @mathhelpforum