SOLUTION: A dehydrated patient needs a 3.6% saline IV. Unfortunately, the hospital only has bags of 2% and 4% saline solutions. How many liters of each of these solutions should be mixed tog

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A dehydrated patient needs a 3.6% saline IV. Unfortunately, the hospital only has bags of 2% and 4% saline solutions. How many liters of each of these solutions should be mixed tog      Log On


   

Question 354034: A dehydrated patient needs a 3.6% saline IV. Unfortunately, the hospital only has bags of 2% and 4% saline solutions. How many liters of each of these solutions should be mixed together to yield 1 liter of the desired concentration?
Found 2 solutions by sofiyac, mananth:
Answer by sofiyac(983) About Me  (Show Source):
You can put this solution on YOUR website!
Let x be the number of liters of 2% saline solution. Since the desired product is 1 liter solution, then the number of liters of 4% saline solution will be 1-x.
+2x%2B4%281-x%29=3.6%2A1+ simplify
+2x%2B4-4x=3.6+ combine like terms
+-2x%2B4=3.6+ subtract 4 from each side
+-2x=3.6-4+
+-2x=-0.4+ divide both sides by -2
+x=0.2+ so we will need 0.2 liters of the 2% solution, and 1-0.2=0.8 liters of the 4% solution.

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let 2% solution added be x liters
4% will be 1-x liters
..
mix = 3.6% 1 liter
...
0.02x +0.04(1-x)= 1*0.036
0.02x+0.040-0.04x=0.036
-0.02x=-0.004
x =0.2 liters of 2% solution
balance -4% will be 0.8 liters
...
m.ananth@hotmail.ca