Coal, Inc. has three mines.Coal from the three mines is transported to a central location where it is processed (in a single production run, using coal from all three mines together), and shipped to four customers.

The cost of producing coal, the ash and sulphur content per ton of coal, as well as the capacity of each mine and demand by each client are found in the worksheet.In addition, the cost of shipping from each mine to each client is also listed.

Quality requirements: ash cannot make up more than 6% of the total coal shipped to each customer, and sulphur cannot make up more than 3.5% of the total coal shipped to each customer.

Determine how to minimise the cost of meeting customer demands?

**this is a sheet from scratch - Excel is NOT needed for this help, I am looking not looking for the final answer, only for help on how to set up:

Variables

Objective (minimise cost of customer demand)

Constraints

in helping me identify these would be greatly appreciated**