A metallurgy company makes two grades of bronze – high grade and low grade. Both types of bronze are made by mixing copper and tin. High grade bronze must be between 65% and 85% copper (by weight), and low grade bronze must be between 45% and 60% tin. High grade bronze sells for $7 per pound, and low grade bronze sells for $6 per pound.
The metallurgy company obtains its copper and tin by extracting it from rock. There are two extraction processes: high yield and low yield. Each hour of high yield extraction requires 4 workers and 3 tons of rock, and produces 30 pounds of copper and 30 pounds of tin. Each hour of low yield extraction requires 3 workers and 2 tons of rock, and produces 25 pounds of copper and 15 pounds of tin. Each day, a total of 120 worker-hours and 100 tons of rock are available.
Formulate an optimization problem (Identify Variables, constraints, and Objective function)