I need a simple formula for Excel

I need a simple formula for Excel that solves the following problem: A coal company has two grades of coal ALMA and BUCK. What is the least expensive mix ratio (percent) of the two coals which will net less than 11% ash and 2.7% sulfur. Use a simple ratio by weight of the two components to calculate the final properties.ALMA is 12.5% ash, 2.2% sulfur, and costs $40.00 per metric ton

BUCK is 8.1% ash, 2.8% sulfur, and costs $50.00 per metric ton

I don't even know where to start with this one. I may in the wrong section of the forum, so any direction someone can give me would be appreciated.

Re: I need a simple formula for Excel

Hey evenforyou.

Instead of doing this for you, I will ask if you can first get the statement into mathematics and then the excel stuff can come later on.

Re: I need a simple formula for Excel

Hey chiro, thanks for the reply. I have an understanding of Algebra but that is as far as my math knowledge extends. I have tried to write an equation for the problem, but with all the variables I am totally at a loss. I don't have a clue where to start. Once I have an equation, I can probably turn it into an Excel statement, it's just figuring out the equation that is stumping me. Thank you for taking the time to respond.