Answer:
4½ cups of flour.
Explanation:
From the recipe card
10 people will be served with bread made using 1 1/2 cups of flour.
Let the amount of flour needed for 30 people = x
We then have:
[tex]\begin{gathered} \text{Number of persons : Amount of Flour Needed} \\ 10\colon1\frac{1}{2} \\ 30\colon x \\ \implies10\colon1\frac{1}{2}=30\colon x \end{gathered}[/tex]We solve the ratio for x.
[tex]\begin{gathered} \frac{10}{\frac{3}{2}}=\frac{30}{x} \\ \text{Cross multiply} \\ 10\times x=30\times\frac{3}{2} \\ 10x=\frac{90}{2} \\ 10x=45 \\ x=\frac{45}{10} \\ x=4.5 \\ x=4\frac{1}{2} \end{gathered}[/tex]Therefore, we will need 4½ cups of flour to make enough bread for 30 people.