A manufacturer produces three models I, II and III of a certain product using raw materials A and B. The following table gives the data for the problem.

	Requirements per unit
Raw material	I	II	III	Availability
A	2	4	4	5000
B	5	2	7	6500
Minimum Demand	200	200	150
Price per unit ($)	40	35	55

The labor time of each unit of model I is twice that of model II and three times of model III. The entire labor force of the factory can produce equivalent of 4000 units of model I. Market requirements specify the ratios 3:2:5 for the production of the three respective models.

1. Formulate the objective function and its constraints.
2. Use solver to find the optimal solution.