Those are the odds of one specific person who hasn't yet won winning both games with only 1 chance for each game. To get the odds of two events happening you simply multiply the odds of one event by the odds of the other. Other than the odds being vastly different, this is just like your chance of flipping a coin and getting heads and rolling a die and getting a 3. For that the odds would be (1 in 2) * (1 in 6) = 1 in 12. Other than needing a calculator it works just th esame for PB and MM: (1 in 195,249,054) * (1 in 175,711,536) = 34,307,511,180,886,944.
Of course the vast majority of people will never just take one single chance at each game and be done with it, so in reality your chances are better than that. Just remember that "better" is a relative term. With odds of 1 in 175 million, if you buy MM 1000 tickets every year you could expect to win only once every 175,000 years. As a practical matter your chances of winning both games is zero, no matter how many tickets you buy.
OTOH, the chances of somebody eventually winning both games is much better. Counting winners who were in pools, there have been at least a few hundred jackpot winners in each game. Since they've already won one of the games, "all" they have to do to win both is win the other jackpot game. If 500 previous MM winners collectively buy 500,000 PB tickets every year there would be a 1 in 195,249,054 / 500,000 chance, or 1 in 390.5 chance that one of them would win PB in that year. 500 previous PB winners buying 500,000 MM tickets would mean a 1 in 351.4 chance that one of them would win MM. Overall that would mean about a 1 in 185 chance of a previous winner winning the other game during the year.