the final simplex tableau?

$2.$ A mining company operates two mines, each producing three grades of ore. The West Summit mine can produce $2$ tons of low$-$grade ore, $3$ tons of medium$-$grade ore and $1$ ton of high$-$grade ore in one hour of operation. The North Ridge mine can produce $2$ tons of low$-$grade ore, $1$ ton of medium$-$grade ore and $2$ tons of high$-$grade ore in one hour of operation. To satisfy existing orders, the company needs to produce at least $100$ tons of low$-$grade ore, $60$ tons of mediumgrade ore and $80$ tons of high$-$grade ore. The cost of each mine varies, depending on conditions while extracting the ore. If it costs $$400$ per hour to operate the West Summit mine and $$600$ per hour to operate the North Ridge mine, how many hours should each mine operate to supply the required amounts of ore and minimize the cost of production? What is the minimum production cost?

A$.$ Set up the objective equation for this problem. Be sure to label the variables you use in your model.