[SQL] Foreign Key for multi PK or design question

[PostgreSQL Admin]

I have a table in which people will have a number of  questions to
answer.  I want those pk to be placed in my user table.  So if  a user
answers three question I want those 3 pk's in the user table (fk).  
What should I be doing?

Thanks in advance,
J

---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
       choose an index scan if your joining column's datatypes do not
       match