Atelephone long- distance carrier charges customers $0.99 for the first 20 minutes and then $0.07 for each minute ( or any part thereof) beyond 20 mins. if mary uses this carrier, how long can she talk for $6.00?

Among the most famous of all meteor showers are the perseids, which occur each year in early august. in some areas the frequency of visible perseids can be as high as 40 per hour. given that such sightings are poisson events, calculate the probability that an observer who has just seen a meteor will have to wait at least five minutes before seeing another.