Creating a formula via VBA

Posting in here cause my buddy said it fits here more:

Hey guys, I work at an ITS department and was trying to come up with a formula/macro for a statistic professor and to no avail, unsuccessful. I have a set amount of numbers 1-10 (everytime a number is picked it cannot be used again). Each row is an event and there are 4 columns, IE:

1 2 3 4
2 3 4 5
3 4 5 6
4 5 6 1
5 6 1 2
6 1 2 3

My question is if I were to pick the number 6 what are the chances that the number 5 will be chosen with it? This has been a very difficult problem for me to solve. Any suggestions and many thanks.