(MONEY Magazine) – You win some, you lose some. The big issue is whether you know how to keep your gains when they occur and cut your losses when they don't. Take our quiz and learn.

1) Oprah gave you a car! (Actually, General Motors gave you a car when you visited Oprah's show.) So who pays the taxes on the gift?

[A] You [B] Oprah [C] General Motors [D] Taxes? What taxes?

ANSWER: A. You're on the hook. By law you have to report any prizes you win in a contest or game show to the IRS as income. When the award isn't simply a wad of cash, the tax is based on its fair market value. That ran to $28,000 apiece for the Pontiac G6s that Oprah dispensed in 2004, resulting in a tax bill of $7,800 for winners in the 28% bracket. That's not a bad deal for a new car, but it's not a free ride either.

2) On moving day, you realize that the last time you moved--10 years ago--you forgot to reclaim your deposit from the gas company. How can you get that money back?

[A] You can't; you have only a year to reclaim deposits. [B] Turn to your state for help. [C] File an appeal with the utility; sometimes it works.

ANSWER: B. Often, money you've lost in a shuffle--from uncashed dividend checks to forgotten bank accounts--ends up with the nearest state government for safekeeping. More than $20 billion in unclaimed property, in fact, awaits its rightful owners. To see if any of that cash is yours and to learn how to retrieve it, visit MissingMoney.com, a site backed by state governments.

3) You want to own gold but don't want to store Krugerrands at home. So you invest in an exchange-traded fund that holds bullion. You're up 45% after 18 months. If you sell, how will the IRS treat your profits?

[A] Like a Krugerrand [B] Like a mutual fund [C] Like a stock

ANSWER: A. The IRS classifies gold as a "collectible" whether it's in the form of gold coins or an ETF that invests directly in the metal. So any profits you make from selling the ETF will, as with other collectibles, be treated as ordinary income, up to a maximum 28% tax on the gain. If you bought an ETF that invests in mining stocks rather than in gold, you'd pay at most 15% in capital-gains tax on shares held for at least a year.

4) On a weekend jaunt to Vegas with old college pals, you surrender $600 to the slots. Can you at least deduct your gambling losses on your tax return?

[A] Yes, it's a sure thing. [B] No dice, buster. [C] You've got a chance.

ANSWER: C. Like casino gambling itself, the tax code is rigged against the lowly gambler. If you rule the roulette table, you have to pay taxes on your winnings. But if you lose more than you win, tough luck: Gambling losses can be used only to offset gambling winnings. And unlike investment losses, gambling losses can't be carried over from one year to the next. To claim a write-off, you'll need plenty of documentation (for details, see IRS Publication 529 at irs.gov).

5) The cool black velvet painting of Elvis that you bought on eBay never arrives. The seller says he's not responsible if it got lost in the mail. Is he right?

[A] No. By law he must pay up. [B] Unfortunately, yes. Next time better spring for UPS. [C] Maybe. Did you read the fine print?

ANSWER: C. If the item gets lost in the mail or otherwise waylaid, the law requires the seller to resolve the problem or send you a refund--unless his eBay sales listing disclaims responsibility for delivery problems. To coax aid from an unresponsive seller, go to eBay's help page and file a dispute. If the other party still won't budge, you may be able to get reimbursed through the auctioneer's purchase-protection program for at least a portion of the money you're out. If you paid by credit card, you may have another option: Ask your card issuer to cancel the transaction entirely.