# Compounding math

by BEATRICE
(ARLINGTON TEXAS)

AN ORDER FOR 6 OZ OF CUSTOM COUGH SYRUP NEEDS TO BE COMPOUNDED. THE DIRECTIONS CALL FOR 45 ML OF 40%,ETHANOL ALCOHOL. AFTER THIS ORDER IS FULLY MIXED, WHAT WILL THE SYRUP'S APPROXIMATE ALCOHOL CONCENTRATION STRENGTH BE ?

 help by: Anonymous confused on how to even start to solve this problem?

 how to do this one by: Anonymous 40% written another way is 40ml/100ml and you're given in the "recipe" that you need 45ml of the 40%. Set up a ratio and proportion where 40ml/100ml = xml/45ml. x = 18. 6 oz. = 180ml. So set up another ratio and proportion where 18ml/180ml = xml/100ml. x = 10 The answer is 10%

 compounding by: Anonymous when I set this problem up, I got 112.5mls .

 for person who got 112.5 ml by: Anonymous could you please show me your work? maybe I can help....

 another way by: Anonymous 40% is 40/100 45x0.4 is 18 6 ounces x 30 equals 180 and 180 divided by 18 is 10

 Explanation by: Anonymous First, you have to find 40% of 45ml,which is 18ml. Then find what % of the total 180ml is 18ml which is easily figured to be 10%

 Final V&S Initial V&S by: Anonymous there is a simple formula to figure out this problemFV- final volume IV- initial volume IS- initial strength FS- final strengthFV: will be 6oz equals 180ml because this is your order this is what you are trying to make so there for it will be your final volumeHint: the FV is higher than the IVIV: will be 45ml because this is what you already have IS: 40% Hint: usually the FV and FS, and IV and IS follow each other so therefore your 40% will be you Initial Strength FS: Which is (X)what you are looking for ... when the problem asks for the percentage your are normally looking for either the IS or FSHint: will always be a percent and the FS is always lower than the IS percentage So now that you have picked all of the information you need to set up your problem... Lets set it upFV/IV cross multiplied it by IS/FS 180ml/45ml cross multiplied by 40%/(x%)= 1800/180(x%)= 10%

 Figuring Percent Strength by: Ptmike Percentage Strength = x/10040ml/100ml; x/45; cross multiply and divide- 40x45, divided by100=18ml. 18ml/180ml ( 6 oz= 180ml) x/100 ( percentage strength. Cross multiply and divide. Answer: 10ml or 10%.

 Try This Way by: Anonymous The easiest way to do this problem is:(concentration 1)(Qty 1)=(Concentration 2)(Qty 2)(40%)(45ml) = (X)(180ml) 6oz=180ml1800%/ML = (X)(180ml)Solve for x by dividing 1800%/ml by 180mlAnswer is 10%

 c1v1=c2v2 by: Anonymous use c1v1=c2v2c1 = unknown (x) v1 = 180ml (1oz = 30 ml to 6 oz = 180ml) c2 = 40% = 40/100 = 0.4v2 = 45mlsolve for c1c1 = c2v2/v1 = (0.4*45)/ 180 ml = 0.1 = 10%