A country's consumption of oil increases 3.1% per year. Assuming this rate of increase, its demand during the next year will be 8,000,000 barrels. The country has 157 years of oil reserves at this rate of consumption.

(a) How much oil will be used at the end of 24 years?
Answer: barrels

(b) How long will the oil reserves last?
Answer: years

(c) If residents of the country can reduce the growth rate of their consumption by 1.5% per year, how long will the oil reserves last?
Answer: years