Final answer:
To make 30 servings of bread with a yeast to flour ratio of 1:200 and 0.25 oz of yeast, you need 50 oz of flour. For 60 servings with a 1:180 ratio and using 90 oz of flour, you need 0.5 oz of yeast.
Step-by-step explanation:
For making 30 servings of bread with a yeast to flour ratio of 1:200, and using 0.25 oz of yeast, we calculate the required amount of flour as follows:
Ratio of yeast to flour is 1:200, so for every 1 ounce of yeast, we need 200 ounces of flour.
Since we have 0.25 ounces of yeast, we multiply 0.25 by 200 to find the required flour amount.
This means we need 0.25 oz × 200 = 50 oz of flour.
For making 60 servings of bread with a different ratio of 1:180 and using 90 oz of flour, we reverse the calculation to find the required amount of yeast:
Now the ratio of yeast to flour is 1:180, meaning for every 1 ounce of yeast, we need 180 ounces of flour.
We set up a proportion (1 oz yeast)/(180 oz flour) = (x oz yeast)/(90 oz flour), where 'x' represents the required amount of yeast.
By solving the proportion, x = (90 oz flour)/(180 oz flour per oz yeast) = 0.5 oz yeast.