Problema Solution
As a nasal decongestant, doctors sometimes prescribe saline solutions with acreate different mixtures, but only needed to stock the 6% and 20% concentrations, since any percentage in between could be obtained with the correct amounts of the two mixtures. An order comes in for a 15% solution. How many milliliter (mL) of the 20% solution must be mixed with 10% mL of the 6% solution to obtain the desired 15% solution?
Answer provided by our tutors
let
x = ml of the 20% solution
y = 10 ml of the 6% solution
20% of the x solution + 6% of the 10 ml solution = 15% of the (x + 10) ml solution
0.2*x + 0.06 * 10 = 0.15*(x + 10)
by simplifying and solving we find
x = 18 ml
18 ml of the 20% solution should be mixed.