1. confusing word problem

A pet supply company mixes two brands of dry dog food. Brand X costs $15 per bag and contains 8 units of nutritional element A, 1 unit of nutritional element B, and 2 units of nutritional element C. Brand y costs$30 per bag and contains 2 units of nutritional element A, 1 unit of nutritional element B, and 7 units of nutritional element C. Each bag of mixed dog food must contain at least 16 units of A, 5 units of B, and 20 units of C. Find the number of bags of brands X and Y that should be mixed to produce a mixture meeting the minimum nutritional requirements and having a minimum cost.

I tried to set up different equations in many ways but they did work out. Does anyone have any ideas how to set it up?

2. Originally Posted by Kitty216
A pet supply company mixes two brands of dry dog food. Brand X costs $15 per bag and contains 8 units of nutritional element A, 1 unit of nutritional element B, and 2 units of nutritional element C. Brand y costs$30 per bag and contains 2 units of nutritional element A, 1 unit of nutritional element B, and 7 units of nutritional element C. Each bag of mixed dog food must contain at least 16 units of A, 5 units of B, and 20 units of C. Find the number of bags of brands X and Y that should be mixed to produce a mixture meeting the minimum nutritional requirements and having a minimum cost.

I tried to set up different equations in many ways but they did work out. Does anyone have any ideas how to set it up?
This is about linear programming, or system of inequalities. Do you understand anything about that? If you have not discussed this yet in class, then there is no use explaining a solution to you here.
The solution is rather long.

3. ooohh I believe I did linear programming before. I just have to find my old notes. Systems of inequalities i've definately done. Thanks =D