For one batch of cookies, the ratio of ounces of butter to ounces of flour is 2 to 3. How many ounces of butter and ounces of flour are needed for 5 batches?
For one batch of cookies, the ratio of butter to flour is 2:3, or $\frac{2}{3}$. For $5$ batches, we have $$5 \cdot \frac{2}{3} = \frac{(5 \cdot 2)}{3}= \frac{10}{3} = \frac{10}{3} \times \frac{3}{3} = \frac{10 \cdot 3}{3 \cdot 3} = \frac{30}{9} =
\boxed{\frac{10}{3}}$$ounces of butter and $5 \cdot 3 =\boxed{15}$ ounces of flour.