Hi I have 2 columns as below..

Col A Col B

Ref# | Name
4565 | ABC
6585 | ABC
4314 | ABC
5648 | MNO
6546 | MNO
8974 | XYZ
1346 | MNO
6584 | XYZ
1366 | ABC
4985 | XYZ
1346 | XYZ
5456 | XYZ

I want to pick Ref# randomly on an average.

Say, in column B there are 40 ABC, 55 MNO, 80 XYZ, 10 PQR and so on.. Then I
need to pick a total on 20 ref# where I have ref# from all the Names on an
average.