A dehydrated patient needs a 7.9% saline IV. Unfortunately, the hospital only has bags of 3% and 10% saline solutions. How many liters of each of these solutions should be mixed together to yield 3 liters of the desired concentration?

Question

mertsj · Answer

x liters of 3%
3-x liters of 10$
.03x + .10(3-x)= .079(3)

anonymous · Answer

ok do I solve for x and y? to get the concentrations from the 3& and the 10% bags?

mertsj · Answer

30x+100(3-x)=237
30x+300-100x=237
-70x=-63
x=.9 liters of 3% solution
3-x = 2.1 liters of 10 % solution

mertsj · Answer

First multiply by 1000 to get rid of the decimals.

anonymous · Answer

ok , I got x = 0.9

anonymous · Answer

so that will be concentration from the 3% bag right?  then I need to find the concentration from the 10% bag correct?

mertsj · Answer

Good!!  That is the amount of 3% solution that is needed.

mertsj · Answer

Exactly

anonymous · Answer

ok ty

mertsj · Answer

yw

hero · Answer

my approach works, I just make mistakes

hero · Answer

x + y = 3
.03x + .1y = .079(3)