Posted by Fatih on .
You are a lab technician and must create 250 ml of a 17% salt solution. You have available three stock solutions. You have a one liter container of a 5% salt, a 500 ml container of a 28% salt solution, and a 400 ml container of a 40% salt solution. Show the work necessary to calculate the cheapest method of preparing the 17% salt solution if the 5% salt solution costs $28 per liter, the 28% solution costs $38 per liter, and the 40% solution costs $50 per liter. Be sure to explain in paragraph form why you have selected the amounts of each and the total cost of your selection.

Calc 
MathMate,
Hint:
The costs are linear, so you can either prepare it with 5%+28% or 5%+40%.
Calculate the cost of each and use the less expensive option.
I have the impression that it costs less by mixing 5% with 40%.