The fish market is selling several kinds of fish. But there aren't any prices listed. You ask about the prices, but all the seller will tell you is this:

1. A pound of salmon and a pound of bass are $12.
2. A pound of bass and a pound of swordfish are $10.
3. A pound of salmon and a pound of swordfish are $8.
4. A pound of swordfish and a pound of catfish are $5.

Each price per pound is a whole-dollar amount. How much is the price per pound for each kind of fish?