Can you walk me through the solution of: Susan wants to throw a party for her mom. She is planning on having 30 guests. For dinner she is making a recipe that makes 2 servings each. Each batch of the recipe calls for 4 potatoes and 1 teaspoon of salt. A potato costs $.10 and a container of salt costs $2 at the supermarket. If each container of salt has 5 teaspoons, how much money will Susan spend on food?