This assignment solution for ECO105 Business Economics addresses several key economic concepts. It begins by analyzing Australia's dependence on Middle Eastern oil and the impact of supply disruptions on passenger car demand, considering the role of electric cars as substitutes. The solution then explores the production possibility frontier (PPF) in the context of Australia's workforce development, examining how government encouragement of further education affects the economy's output. Furthermore, it delves into the determinants of long-term economic growth, including the role of monetary and fiscal policies. Finally, the assignment analyzes the impact of sales tax on cigarettes and compares the market structure of the Australian supermarket industry to an oligopoly, specifically focusing on Coles and Woolworths. The solution incorporates diagrams and references to support the analysis and conclusions.