Assumptions
1. Author had the salt to start with, with Amber sitting on the opposite side of the table.
2. Amber had the pepper to start with.
3. Amber handed the pepper directly to Chris, bypassing Becky
Therefore, Salt from Author to Amber = 2 units. (He had to 'slide' it to her because she was too far away to pass it directly).
Salt from Amber to Chris = 1 unit (passed directly)
Pepper from Amber to Becky = 1 unit.
Therefore
2 = 2????