Results 1 to 4 of 4

Math Help - 2 Problems, need help, story problems!

  1. #1
    Junior Member
    Joined
    Oct 2007
    Posts
    73

    2 Problems, need help, story problems!

    1.) suppose that you have a solution with 15% alcohol by volume and then you add to your orignial solution, an additional 20 milliteres of pure alcohol. If the resulting solution consists of 49% alcohol by volume, then how much alcohol do you have? (hint: Pick a variable for the amount of solution that you begin with, an dfind two different expressions for the final amount of alcohol.

    2.) Suppose that youare planning a fence to surround a region with three sides, One side of this region is 60 feet long, but you don't know yet how long the other sides are. However you do know that one of these sides is twice as long as the other. Hint: draw a picture. If the total length of the fencing available is 300 feet, then how long can each side be?

    THANK YOU FOR YOUR HELP, I'M STUPMED! PLEAS HELP!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Eater of Worlds
    galactus's Avatar
    Joined
    Jul 2006
    From
    Chaneysville, PA
    Posts
    3,001
    Thanks
    1
    Let x = the amount of alcohol you started with. You don't need two equations. Just one.

    0.15x+20=0.49(x+20)

    Solve for x.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Oct 2007
    Posts
    73
    Thanks galactus, that's what I had but wasn't sure it was right, any idea on number 2? Thanks again!
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member
    Joined
    Oct 2007
    Posts
    178
    For number 2,
    I think I got something.

    x + 60 + y= 300
    I doesn't specify whether which side is 2 times bigger so we will have y is 2 times bigger, which equals 2x=y

    You mow have 2 equations for two unknown variables.
    SUbsititute, solve for x, then solve for y.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. 3 story problems
    Posted in the Algebra Forum
    Replies: 2
    Last Post: November 10th 2008, 07:28 AM
  2. Story Problems!
    Posted in the Algebra Forum
    Replies: 4
    Last Post: October 22nd 2008, 10:07 PM
  3. Story Problems
    Posted in the Algebra Forum
    Replies: 3
    Last Post: October 11th 2008, 05:45 PM
  4. Story Problems
    Posted in the Math Topics Forum
    Replies: 5
    Last Post: May 7th 2007, 04:31 AM
  5. Help (story problems)
    Posted in the Algebra Forum
    Replies: 2
    Last Post: March 6th 2007, 06:54 AM

Search Tags


/mathhelpforum @mathhelpforum