A sausage factory can produce European wieners at a rate

A sausage factory can produce European wieners at a rate of 500 kg per day. It supplies wieners to local stores and restaurants at a steady rate of 100 kg per day. The cost to prepare the equipment for producing European wieners is $12. Annual holding cost is $4 per kg of wieners. The factory operates 300 days a year. Calculate:
a. The optimal production run quantity.
b. The number of production runs per year.
c. The length (in days) of a production run.