Imagine there's a giant directory containing the names of every woman, man, and child living in the United States, and we pick one of them at random.

Now, guess which one.

Not crazy about your chances? That long shot — one in 325 million — is only slightly more remote than the one-in-302,575,350 chance of winning the jackpot in the Mega Millions lottery game.

Under the rules of the game, those slim odds are the same no matter the size of the jackpot, which had swelled to an outlandish $1 billion by Friday afternoon — with the next drawing scheduled for Friday at 11 p.m. Eastern time. Powerball, the other big multistate lottery, is in the same ballpark of likelihood, with the chance of winning the jackpot at one in 292,201,338.

Here are some other guessing games that are easier:

  • Pick out a single word from the complete set of Harry Potter books, which total a mere 1,084,170 words, according to (Heck, we could ask you to guess a single word from 250 copies of the complete J.K. Rowling series — 1,750 volumes, with 271 million words in all — and you'd still have a better shot than winning the lottery jackpot.)

  • Select an individual minute from the roughly 276,000,000 minutes that have elapsed since Christopher Columbus made his first landing in the Americas.

  • The distance from Philadelphia to Los Angeles is 2,710 miles — about 172 million in inches. Guess which inch we have in mind.

  • Three Olympic swimming pools hold about 253 million ounces of water combined. Feeling lucky? Pick an ounce.

Or, just buy a Mega Millions ticket.

And good luck. You'll need it.