According to the US Geological Survey, on average there are 150 earthquakes of magnitude 6.0 or greater per year worldwide, which translates to an average of .41 quakes per day (source: earthquake.usgs.gov). Assume that all the Poisson conditions regarding independence, etc., are met. How likely is it that the time until the next quake of this magnitude will be
a. At least 3 days?
b. Between 1 and 2 days?
c. Less than 4 days?