Please note: probability is not my strong suit, so you should probably double-check this solution. However, I think it is correct...

The winning possibilities are picking 6, 5, 4 or 3 correct numbers. The total probability of winning, then, is the sum of the probability of getting 6, 5, 4 and 3 correct numbers. It's easy to find the probability for getting all six:

To find the probability of five successes, we must first determine the total possible combinations:

The probability of five successes is the sum of the probabilities of each individual combination of five successes:

In fact, we can generalize this:

Conversely, the probability of not winning is simply:

and the probability of not winning 91 times in a row is:

The probability of losing each encore ticket:With encore (keeping it simple) a player has 2, 1 in 10 chances of winning something per play.

The probability of losing eight of these is:

Just multiply the probabilities:What are the odds that nothing will be won from this lot of tickets?

I'll let you compute that.