150 mls of a 7% solution is required available 20% and 0.5% liter bottles solve.

Mathematics
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Dilution Problem

Oct 21st, 2014

let a milliliters = amount of 20% solution used

let b milliliters = amount of 0.05% solution used

Then a + b = 150    (total amount used = 150)            (*)

and 0.2 a + 0.005 b = 150 x 0.07    ( concentrations before and after mixing is same)

or     20a + 0.5b =  1050                    (multiplying by 100 )

or     40a + b = 2100                            (multiplying by 2 )

but       a + b = 150    from equation       (*)

So      39 a   = 1950   (subtracting the two equations)

             a = 1950/39 = 50

Hence 50milliliters of 20% solution should be mixed with 100 milliliters of 0.005 % solution to get 150milliliters of 7 % solution


Oct 21st, 2014

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Oct 21st, 2014
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Oct 21st, 2014
Dec 9th, 2016
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