David ate 323 apples and Jamal ate 539 apples. If they finished all the apples in a box, how many apples were in the box?

The total number of apples in the box is 323 + 539 = <<323+539=862>>862. Answer: \boxed{862}.

To find out how many apples were in the box, we can add the number of apples David ate to the number of apples Jamal ate.

David ate 323 apples.
Jamal ate 539 apples.

Adding these two numbers together:
323 + 539 = 862

Therefore, there were 862 apples in the box.

To find out how many apples were in the box, we need to add the number of apples David and Jamal ate.

David ate 323 apples.
Jamal ate 539 apples.

To find the total number of apples in the box, we add these numbers:

323 + 539 = 862

Therefore, there were 862 apples in the box.