<s>[INST] A chemical plant produces three chemicals per day, and the supply and demand are as follows:

| Chemical | Supplied (per day) | Demanded (per day) |
|----------|--------------------|--------------------|
| A        | 600                | 650                |
| B        | 500                | 400                |
| C        | 800                | 700                |

The chemical plant needs to adjust its production to meet the demands. The production cost for each chemical per day is as follows:

| Chemical | Production Cost (per day) |
|----------|--------------------------|
| A        | $200                     |
| B        | $300                     |
| C        | $250                     |

The plant can also store unsold chemicals. The storage cost for each chemical per day is as follows:

| Chemical | Storage Cost (per day) |
|----------|------------------------|
| A        | $10                     |
| B        | $30                     |
| C        | $20                     |

To minimize costs, the chemical plant wants to adjust its production to meet the demand and store the minimum amount of unsold chemicals. Formulate this problem as a linear programming model.[/INST]