Answer:
44
Step-by-step explanation:
Lunch = 3 appetizers per guest
If there are 22 guests:  22 × 3 = 66 appetizers served
Dinner = 5 appetizers per guest
If there are 22 guests:  22 × 5 = 110 appetizers served
Difference = total dinner appetizers  - total lunch appetizers
         = 110 - 66
         = 44