To find out how much sugar Molly would use for 3 \( \frac{1}{3} \) batches of cookies, we start with the amount of sugar needed for one batch, which is 5 cups.
First, we need to express 3 \( \frac{1}{3} \) as an improper fraction:
\[ 3 \frac{1}{3} = 3 + \frac{1}{3} = \frac{9}{3} + \frac{1}{3} = \frac{10}{3} \]
Now, we can calculate the total amount of sugar needed for \( \frac{10}{3} \) batches:
\[ \text{Sugar for } \frac{10}{3} \text{ batches} = 5 \text{ cups/batch} \times \frac{10}{3} \text{ batches} \]
This can be calculated as follows:
\[ = 5 \times \frac{10}{3} = \frac{50}{3} \]
Now, converting \( \frac{50}{3} \) into a mixed number:
\[ 50 \div 3 = 16 \quad \text{(remainder 2)} \]
This means:
\[ \frac{50}{3} = 16 \frac{2}{3} \]
Thus, Molly would use \( \frac{50}{3} \) cups or \( 16 \frac{2}{3} \) cups of sugar to make 3 \( \frac{1}{3} \) batches of cookies.
The final answer is:
\[ \frac{50}{3} \text{ cups of sugar} \quad \text{or} \quad 16 \frac{2}{3} \text{ cups of sugar} \]