I'm struggling in this question. Please help me explain, thank you so much!

1. Suppose a city is hit by a tornado that destroys 25 percent of the housing in the area. Would you expect the total expenditure on housing after the tornado to be greater than, less than, or equal to what it was before the tornado? Explain your answer.
2. How might you determine whether toothpaste manufacturers and mouthwash manufacturers are competitors?
3. A tax is placed on the sellers of a good. What happens to the percentage of this tax that buyers pay as the price elasticity of demand for the good decreases? Explain your answer.
4. List determinants of the price elasticity of demand.