Ya the correct answer must be E

as using first statement we can authoritatively get the nos of seats occupied (using unoccupied info) in the first 20 rows but we cannot comment about the last 5 rows hence NOT SUFF

same logic works for the second statement.

However if we sum up the two statements & look at them, then also we cannot conclude on the occupancy as there will be 10 rows which overlap in both the statements & since they are averages we cannot narrow them out i.e we cannot extract a part or idividual info( nos of seats unoccupied here).