I need help with this. What formula we use.

The answer for

a)1.63 * 10^-6

b) 3.91 * 10^-5

c) 0.01 cancer/year

The drinking water supply for a town of 18,000 residents has been contaminated with highly toxic vinyl chloride as a result of a chemical spill. Suppose a 70 kilogram adult drinks 2 liters of water every day for 2 years (before moving out of town) with a vinyl chloride concentration of 0.002mg/L. The potency factor for vinyl chloride is 2.3(mg/kg-day)1. (a) Given an average life expectancy of 70 years, what is the incremental lifetime risk for this individual due to this exposure to vinyl chloride? (b) What is the incremental lifetime risk to residents of the town who do not move away? Assume the average town resident will spend 350 days per year, for 50 years, living in the town. (c) How many cancers per year would you expect to see in the town among the population of residents who do not move away