What I mean was:

Currently, there are 2 extents in the EMP segments of size (5242880 each). Hence the total size of the segemnts comes to 5242880 + 5242880 = 10485760 bytes. However, it doesn't mean that the second extent is fully utilized. The second extent is out there and may be partly filled up. When the second extent is fully utlilized, then a thrid extent of 5242880 bytes would be allocated (if PCTINCREASE = 0).

Hope this clarifies.