A coffee shop sells two types of coffee beans: premium Arabica beans for $15 per pound and standard Robusta beans for $10 per pound. A customer buys pounds of Arabica beans and pounds of Robusta beans. The total cost, , in dollars, for the purchase can be modeled by the equation . If the customer spent a total of $75 on Robusta beans and the total cost for the entire purchase was $180, how many pounds of Arabica beans did the customer buy?
5
7
8
10
