In simple random sampling, it is also true that each member of the population is equally likely to be selected, the chance for each member being equal to the sample size divided by the population...

In simple random sampling, it is also true that each member of the population is equally likely to be selected, the chance for each member being equal to the sample size divided by the population size.

a. Under what circumstances is that fact also true for systematic random sampling? Explain your answer.
b. Provide an example in which that fact is not true for systematic random sampling.