Results 1 to 8 of 8

Math Help - Help with Math WordProblem

  1. #1
    Newbie
    Joined
    Jan 2011
    Posts
    16

    Help with Math WordProblem

    A 1000L Tank contains 50L of a 25% brine solution. You add x liters of a 75% brine solution to the ank.
    a)Show that the concentration C, the proportion of brine to total solution, in the final mixture is:
    C= (3x+50)/(4(x+50))
    b)Determine the domain of the function based on the physical constraints of the problem. Explain your answer.
    c) Graph the concentration function. As the tank is filled, what happens to the rate at which the concentration of brine is increasing? What percent does the concentration of brine appear to approach?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1
    Quote Originally Posted by thelensboss View Post
    A 1000L Tank contains 50L of a 25% brine solution. You add x liters of a 75% brine solution to the ank.
    a)Show that the concentration C, the proportion of brine to total solution, in the final mixture is:
    C= (3x+50)/(4(x+50))
    b)Determine the domain of the function based on the physical constraints of the problem. Explain your answer.
    c) Graph the concentration function. As the tank is filled, what happens to the rate at which the concentration of brine is increasing? What percent does the concentration of brine appear to approach?
    1000 litres is simply the capacity of the tank.

    The total solution is 50 litres plus x litres

    25\%=\frac{25}{100}=\frac{1}{4}

    75\%=\frac{3}{4}

    Therefore, the amount of brine in the solution, in litres, is

    \frac{1}{4}(50)+\frac{3}{4}(x)

    Try writing the fraction of brine divided by total amount of solution.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jan 2011
    Posts
    16
    alright how about the domain based on physical constraints of the problem
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1
    The physical constraint relates on the fact that the solution cannot exceed 1000 litres.
    That creates an upper bound for x.
    The maximum value of the solution reveals the domain.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Jan 2011
    Posts
    16
    So is the domain X cant equal -50 cuz that doesnt make sense
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1
    No, x can't be negative at all, since a measurement in litres cannot drop below zero.

    The solution of 50+x litres cannot exceed 1000 litres.
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie
    Joined
    Jan 2011
    Posts
    16
    Yea so it is basically x must equal 950 or less??


    And also can you answer the last question part c because when I graphed it on my calc it did not show
    Follow Math Help Forum on Facebook and Google+

  8. #8
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1
    Yes, x is from 0 to 950.

    When x=0, the value of the fraction C is 50/200=1/4.
    As x increases towards 950 (and beyond if it was physically possible), the graph approaches \frac{3x}{4x}=\frac{3}{4}

    Hence, the graph continues to increase from C=1/4 towards C=0.75
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Another Math WordProblem
    Posted in the Pre-Calculus Forum
    Replies: 5
    Last Post: February 10th 2011, 05:15 PM
  2. WordProblem with percentages
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 10th 2011, 05:02 PM
  3. Replies: 1
    Last Post: June 2nd 2010, 09:49 AM
  4. Some Trig Wordproblem Guidance
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: April 20th 2009, 02:59 PM
  5. Measure of Degree Wordproblem...
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: August 16th 2008, 03:51 AM

Search Tags


/mathhelpforum @mathhelpforum