3 Major avalanches can be regarded as randomly occurring events. They occur at a uniform average rate of 8 per year.
- Find the probability that more than 3 major avalanches occur in a 3-month period.
- Find the probability that any two separate 4 -month periods have a total of 7 major avalanches.
- Find the probability that a total of fewer than 137 major avalanches occur in a 20 -year period.