The problem asks how many cups of flour are needed for 3 batches of cookies, with each batch requiring $2 \frac{1}{2}$ cups of flour.

Step-by-step solution:

1. Convert the mixed number $2 \frac{1}{2}$ into an improper fraction: $2 \frac{1}{2} = \frac{5}{2}$
2. Multiply the amount of flour for one batch by the number of batches (3): $3 \times \frac{5}{2} = \frac{15}{2}$
3. Convert $\frac{15}{2}$ back into a mixed number: $\frac{15}{2} = 7 \frac{1}{2}$

Thus, $7 \frac{1}{2}$ cups of flour are needed for 3 batches.

The correct answer is 7 1/2 cups.

Would you like more details or have any questions?

Here are 5 related questions for practice:

1. If a recipe requires $3 \frac{1}{4}$ cups of flour per batch, how many cups are needed for 4 batches?
2. How many cups of flour are needed for 5 batches if each batch uses $1 \frac{2}{3}$ cups?
3. A recipe calls for $4 \frac{1}{3}$ cups of sugar per batch. How much is needed for 2 batches?
4. What is the total flour needed for $2 \frac{2}{5}$ cups per batch over 6 batches?
5. How do you convert $6 \frac{3}{4}$ into an improper fraction?

Tip: When multiplying fractions, always convert mixed numbers to improper fractions first for easier calculation!