Determine if the demand for the following products is price elastic or price inelastic, and explain your answer. In your explanation, be sure to include how the necessity of a good and the availability of substitutes affect the price elasticity of demand in each of these specific cases:
• Gasoline as a commodity
• Gasoline sold at a local gasoline station
• Hotel rooms for people planning a vacation
• Hotel rooms for people on business to meet an important client