Chapter 4.7, Problem 35E

Coal, steel. An economy is based on two industrial sectors, coal and steel. Production of a dollar's worth of coal requires an input of $\$0.10$ from the coal sector and $\$0.20$ from the steel sector. Production of a dollar's worth of steel requires an input of $\$0.20$ from the coal sector and $\$0.40$ from the steel sector. Find the output for each sector that is needed to satisfy a final demand of $\$20$ billion for coal and $\$10$ billion for steel.