Final answer:
To make 6 servings of Andrea's recipe, 10 1/2 lemons would be needed.
Step-by-step explanation:
To find the number of lemons used to make 6 servings of Andrea's recipe, we need to first determine how many lemons Lois uses per serving and how many lemons Andrea uses per serving.
Lois uses 4 1/2 lemons for 3 servings, which means she uses 4 1/2 / 3 = 1 1/2 lemons per serving.
Andrea uses 1/4 of a lemon more per serving than Lois's recipe. So, she uses 1 1/2 + 1/4 = 1 3/4 lemons per serving.
To find the number of lemons needed for 6 servings of Andrea's recipe, we multiply the number of lemons per serving by the number of servings: 1 3/4 x 6 = 10 1/2 lemons.
Therefore, 6 servings of Andrea's recipe would require 10 1/2 lemons.