Question - Market Demand - In Gas Pump, South Dakota, every Buick owner's demand for gasoline is 20 - 5p for p less than or equal to 4 and 0 for p > 4. Every Dodge owner's demand is 15 - 3p for p less than or equal to 5 and 0 for p > 5. Suppose that Gas Pump has 100 Buick owners and 50 Dodge owners. If the price of gasoline is 4, what is the total amount of gasoline demanded in Gas Pump?
(a) 300 gallons
(b) 75 gallons
(c) 225 gallons
(d) 150 gallons