Melissa owns a catering company . For lunch and dinner parties , she serves appetizers before each meal. The number of appetizer
s Melissa serves is directly proportional to the number of guests at the party. For lunch parties, she serves 3 appetizers per guest. For dinner parties, she serves 5 appetizers per guest. When serving 22 guests, what is the difference of the number of appetizers she serves for dinner and the number of appetizers she serves for lunch?
