The two countries of Botkinlandia and Kellertopia share one single power plant with a maximum capacity of 10 gigawatts (10 billion watts = 10,000,000 kW). Kellertopia is small and prosperous, with a stable population of 500,000 and average energy use of 8 kW per capita. Botkinlandia is larger (pop.=1,000,000), less developed (per capita energy use = 1
kW), and growing fast (population and per capita energy use doubling every 20 years).
Today, Kellertopia uses 80% of the electricity generated. What percent will it use in 40 years?
a) 20%
b) 25%
c) 33%
d) 50%
e) 67%