Solenoid vs the starter, Newfoundland, Canada

[lavallee <llavalle@atcon.com>]

To any lister would can help:
I am new to the list. I enjoy the list information very much. If I were. or
could chose a board of directors for an Audi service business I'd chose
every person on this list.

It happened again. 
Turned off the 87 5000-S in a Wal-Mart parking lot and it wouldn't restart.
A man getting in his 86 Quattro told me it was a weak spot on the starter
and that it might start if I tap the starter with a hammer. 

Back to Wal-Mart to buy a rubber mallet. 

Returnig to the car another person helped by tapping the starter - that
didn't work. He then tapped the solenoid. The car started. He told me the
soleniod was faulty. 

Questions:
1. Is the starter defective?
2. Is the soleniod defective?
3. Are both defective?
4. Can I buy the soleniod or the starter separate? And where do you suggest?

Thanks,
Larry