Final answer:
The number of possible lunch special combinations at Deb's Deli is 35.
Step-by-step explanation:
To calculate the number of possible lunch special combinations at Deb's Deli, we need to consider that a customer can choose a sandwich and a salad or a sandwich and a soup. There are 5 choices of sandwiches, 4 choices of salad, and 3 choices of soup.
Using the multiplication principle, we can multiply the number of choices for each option to find the total number of combinations. So, the number of possible lunch special combinations is 5 (choices of sandwich) × 4 (choices of salad) + 5 (choices of sandwich) × 3 (choices of soup) = 20 + 15 = 35.