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Mega Millions jackpot grows to $640 million -- could go higher

The Mega Millions lottery hit $640 million Friday, according to lottery officials, raising what was already a record-shattering prize.

That's a cash payout of $462 million, according to the Mega Millions web site.  

The even larger prize is expected to add to the lottery frenzy across the country. Hopeful future-millionaires have formed long lines at stores across the 42 states, plus Washington, D.C. and the Virgin Islands, where tickets are sold.

What to buy when you win the jackpot

The drawing for the fortune is set for late Friday in Atlanta.

Ticket sales in California are expected to hit $333 million, with $189 million in New York and $94 million in Texas. In all, the lottery is expected to generate sales of $1.4 billion for this drawing.

Nobody matched all six numbers in Tuesday's regular draw, and the total jackpot has been growing since.    

Players pay $1 for a ticket and must pick five numbers from 1 to 56 plus a Mega number from 1 to 46 to win the jackpot.

But at $1 a ticket, what are the odds of picking a Mega Millions winning ticket -- even at a "lucky" store?

According to Dr. Ken Alexander, a mathematics professor at USC, the odds of winning are one in 175.7 million. That raises the question: Why not guarantee you win by buying all possible ticket combinations?

“Well, a number of things get in the way of that,” Alexander said.

Assuming 350 million tickets are sold, there’s a better than 90 percent chance that there will be at least two winners. So after taxes, you’ll likely come out with a loss.

And, assuming it takes about five seconds to fill out each card, you'd need five years to mark the bubbles on the game tickets. There goes that plan.

A student and her friend dropped a more reasonable $20 at a 7-11 near USC Thursday for 20 tickets. That made Michelle Chong's odds of winning 1 in 9 million -- daunting odds, but at least she bought herself some excitement Friday.

"It's just the excitement that you might win," said Chong. "The number is so big."

Why even skeptics are rushing to buy a Mega Millions ticket

Had Chong purchased 50 tickets, her chances of winning the jackpot would be comparable with her odds of being struck by lightning.

Based on U.S. averages, you're about 8,000 times more likely to be murdered than win the lottery and 20,000 times more likely to die in a vehicle crash.

But what about the strategy of choosing outlets that have previously sold winners?

"If you buy them from some store that sells a lot of tickets, then the store is more likely to have a winner,” Alexander said. “But your 10 (tickets) have the same probability as if you buy them from anywhere else.” 

The largest Mega Millions jackpot ever won was $390 million in March 2007, when the prize was split between two tickets sold in Georgia and New Jersey. The largest Powerball jackpot was $365 million won in 2006 on one ticket held by eight workers at a Nebraska meatpacking plant.

Patrick Healy and John Simerson of contributed to this report.

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