There are a total of 20 snacks in each bag. We consider the probability of picking a bag of peanuts with reduced sodium and then a granola bar with reduced sodium, then multiply by 2 (because we could pick them in the other order).
There is a 5/20 chance of picking a sodium-reduced bag of peanuts first, and a 2/20 chance of picking a sodium-reduced granola bar next. Thus, the chance of picking them together in that order is 5/20*2/20=10/400, or 1/40. Because we could pick the snacks in either order, we multiply by two, for a result of a 1/20 probability.