Algebra word problem

Question

How many liters of a 15% NaCl solution should be mixed with 2 L of a 20% NaCl solution to obtain a 16% NaCl solution?

Answer 1

Hi Tanya,

 

Let X = liters of 15% NaCl solution.

 

.15X + (2)(.2) = .16(X + 2)--> the final volume equals the initial volume of 20% solution plus the volume of 15% solution that has been added.

 

.15X + .4 = .16X + .32

 

.08 = .01X

 

x = 8 liters