Catalina had \( 6 \frac{3}{4} \) cups of flour. She used \( 2 \frac{1}{2} \) cups of flour in one recipe and \( 2 \frac{1}{4} \) cups of flour in another recipe. How much flour does she have left?

To find out how much flour Catalina has left, we first need to add the amounts of flour she used in both recipes and then subtract that from the total amount she started with. First, let's convert all fractions into improper fractions: \( 6 \frac{3}{4} = \frac{27}{4} \) cups of flour. For the flour used in the first recipe: \( 2 \frac{1}{2} = \frac{5}{2} = \frac{10}{4} \) cups of flour. In the second recipe: \( 2 \frac{1}{4} = \frac{9}{4} \) cups of flour. Now, we add the flour used in both recipes: \[ \frac{10}{4} + \frac{9}{4} = \frac{19}{4} \text{ cups} \] Next, we subtract this from the total flour: \[ \frac{27}{4} - \frac{19}{4} = \frac{8}{4} = 2 \] So, Catalina has \( 2 \) cups of flour left.