1) Here's the diagram:
The primary key of this relation is [part #, vendor name].
2) There is one primary key in this relation.
3) There are two fields (attributes) in the primary key.
4) Here's the determinancy diagram:
The database table descriptions look like the following:
VendorPart(part#*, vendor*, unit cost)
The database tables look like the following:
Back to original problem.