I need the objective function for minimization problem of overall cost of choosing factory (a), First table show how much product ship and cost of it, second table show cost of factory. I will complete other factory by myself but need to understand first. Constraints are showing below. Please help me.

Cost per Unit Shipped ($1,000's) Existing Factory 2 3 a Potential Factory b Silo 1 4 1 3 6 3 4 8 2 4 8 5 1 6 1 Nm m 00 00 + 3 6 8 00 8 8 1 00 8 N 00 4 3 4 1 4 6 5 7 7 8 1 5 w 00 6 4 5 3 3 00 6 7 8 5 4 8 7 7 8 N 5 1 1 2 NO 6 2 3 2 3 W N N N 00 7 8 9 7 8 Site a Operation cost of new factory (thousand) 620 570 540 b N Constraints Silo Capacity (thousand tons) 1 70 60 3 62 4 65 5 83 6 48 7 52 40 9 240 Factory 1 2 3 New Factory (a/b/c) N Need(thousand tons) 200 120 160 240 8 9 Cost per Unit Shipped ($1,000's) Existing Factory 2 3 a Potential Factory b Silo 1 4 1 3 6 3 4 8 2 4 8 5 1 6 1 Nm m 00 00 + 3 6 8 00 8 8 1 00 8 N 00 4 3 4 1 4 6 5 7 7 8 1 5 w 00 6 4 5 3 3 00 6 7 8 5 4 8 7 7 8 N 5 1 1 2 NO 6 2 3 2 3 W N N N 00 7 8 9 7 8 Site a Operation cost of new factory (thousand) 620 570 540 b N Constraints Silo Capacity (thousand tons) 1 70 60 3 62 4 65 5 83 6 48 7 52 40 9 240 Factory 1 2 3 New Factory (a/b/c) N Need(thousand tons) 200 120 160 240 8 9