If you played a One-Dollar chance for the Megamillions Lottery game, a one-dollar chance every Friday and every Tuesday, at 1 in 258,890,850 odds probability, you could assume that, on average, it would take One Million Four-Hundred and Eighteen Thousand-Five Hundred and Eighteen (1,418,517.999) Years to win. That's, of course, on average. If you are particularly unlucky, it could be much, much longer.
