Hi I have date arranges in cells as

Cell# Column A Column B
1 Name1 10
2 20
3 SUM( 30)
4 Name 2 20
5 50
6 SUM(70)
7 <Blank
8 Name 3 20
9 SUM(20)

I have name of employee in Column A and there total marks in Column B in
Cell - SUM
What I want to do is to calculate the average for only those employees whose
name is enetered in Column, the average is calculated for the column B of
cells SUM.

Please advise