The school cafeteria ordered nineteen red apples and twenty-five green apples for student's lunches. But, if only six students wanted fruit, how many extra did the cafeteria end up with?

The cafeteria ordered a total of 19 + 25 = 44 apples.

Since only 6 students wanted fruit, they only needed 6 apples.
Therefore, the cafeteria ended up with 44 - 6 = 38 extra apples.