Question: how many different combinations of maternal and paternal chromosomes are possible?
Answer: Maternal and paternal chromosomes are randomly distributed on either side of the metaphase plate. So for each pair there's a 50/50 chance as to which side the homologs will go on (8.17). We have 23 pairs each with 50/50 probabilities. That works out to 223 possible combinations of gametes from one human individual.