To determine which serving size has a different ratio of serving size to pounds of meat, we can calculate the ratio for each serving size.
- For 20 servings: \( \frac{20}{2} = 10 \)
- For 40 servings: \( \frac{40}{6} \approx 6.67 \)
- For 80 servings: \( \frac{80}{8} = 10 \)
- For 120 servings: \( \frac{120}{12} = 10 \)
Now we compare the ratios:
- 20 servings: 10
- 40 servings: 6.67
- 80 servings: 10
- 120 servings: 10
The ratio for 40 servings is different from the other ratios.
Therefore, the answer is 40 servings.