Anthropology homework help

I was having trouble with this question: If the nominal GDP is $559 billion in the base year, and it rises to 577 in Year 1, and 605 in Year 2, what is the real GDP in each year, given that the price index has risen from 100 to 104.5 in the first year and up to 108.3 in the second year? If the price index 20 years before the base year was 41.2, and the nominal GDP for 20 years before the base year was 191.0, what was the real GDP for that year? Show your work in all cases.