[general_re]

Note that if there were only 100 numbers in the lottery, then you would win with certainty in case A)

If you make sure that you cover all 100 possible numbers - if your tickets are randomly generated, there's a fair chance that you'll omit at least one number between 1 and 100, and thereby lower your chances to something somewhat less than 100% ;)

[monkey]

I've never played the lottery. Isn't random generation just an option? I always hear about winners "lucky numbers". The point is that you could guarantee a win if you so chose. Of course, in option B), you might win multiple times.

You may have heard about the (Australians?) who bought massive numbers of tickets in lotteries that had accrued big jackpots (and positive expected gains). I'm sure they weren't generating tickets randomly (and I'd hate to get behind them at the 7-11).