About how many commercial banks are operating in the United States?

Which of the following is an example of comparative statics?

A) The estimation of the supply of a good when the wage rate of labor changes from $30 to $10 per hour B) The estimation of the ideal number of workers a firm should hire when wage rate is $20 per hour C) The estimation of the quantity demanded of a good when its price is $5 D) The estimation of the demand for a particular good when consumer income is $10

When E decreases by 3%, we know that

A) a real appreciation will occur if P also falls by 3%. B) a real depreciation will occur if P increases by 3%. C) nominal appreciation. D) nominal depreciation.