A nurse has two solutions that contain different concentrations of a certain medication. One is a 30% concentration and the other is a 15% concentration. How many cubic centimeters of each should she mix to obtain 45 cc of a 20% solution?

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Answer 1 · 2016-02-14T10:51:17

30% medication: 15cc
15% medication: 30cc

Let #x# be the amount of 30% concentration medication needed
#=> 45 - x# is the amount of 15% concentration medication needed

#0.30x + 0.15(45 - x) = 0.20(45)#

#=> 30x + 15(45 - x) = 20(45)#

#=> 30x + 675 - 15x = 900#

#=> 15x = 225#

#=> x = 15#

#45 - x = 30#