A local microbrewery believes it produces the best tasting dark beer in town. To make its case, seven volunteers are asked to participate in a beer tasting contest. Each volunteer is asked to taste 5 dark beers; one is microbreweries, the other 4 are national favorites, and to pick the one he/she prefers.
When answering the questions that follow, assume there is no taste preference for any of the beers (chance alone determines each selection).
What is the probability that none of the volunteers pick the microbrewery's beer?