Final answer:
The question seems to focus on the expected number of audits and related probabilities, which entails statistical calculations requiring specific audit rate information that has not been provided. It's a mathematical problem involving probability and statistics, typically addressed at the high school level.
Step-by-step explanation:
The risks involved in the audit process can be complex and varied. However, the question seems to have been misunderstood, as the student appears to be asking about the number of audits expected over a period, and the probabilities associated with being audited. This is a mathematical problem, likely related to probability and statistics. To address part d, one would need additional information about the audit rate to calculate how many audits are expected in a 20-year period.
For part e, the probability that a person is not audited at all would depend on the audit frequency. However, without specific risk or rate information, this cannot be calculated. Part f requests the calculation of the probability that a person is audited more than twice, which again depends on the underlying statistical model or audit rate. If the audit probability per year were known, one could use a Poisson distribution or another appropriate model to find this probability.