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Question:

livsmom03
livsmom03
Student
College - Junior

I have a prescription for aminosyn 2.5% 500ml. On the pharmacy shelf, I only have a 8.5% 500ml. How do I prepare this order?

I know the answer is to add 235 ml of 8.5% aminosyn with steril water to 500 ml. I need to know the steps to getting that answer. It's obviously some sort of dilution. I need that 8.5 to get down to 2.5 in 500ml...but how, what are the steps/formula?

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Posted by livsmom03 on Monday January 19, 2009 at 10:18 AM and tagged with math, percents, pharmacy, ratios.

Answers:

  1. mcetner
    mcetner Teacher
    High School - 12th Grade

    eNotes Editor

    Let's say you don't know how much aminosyn to add to how much water, which I assume is the problem.  Let the amount of aminosyn be x, and the amount of water be y.

    Then, x + y = 500.

    Also, you know how much pure aminosyn you need, so

    8.5% of x + 0% of y = 2.5% of 500

    .085x +0y = .025(500)

    Now you have a system of equations:

    x + y = 500

    .085x + 0y = .025(500)

    Solve them and you will get the answer you want.

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    Posted by mcetner on Saturday February 7, 2009 at 5:07 AM