When a tax of $1.00 per gallon is imposed on sellers of gasoline, the supply curve for gasoline shifts upward, but by less than $1.00

The income per capita of Ruberia in a certain year was 7,240 rubies and the income per capita of U.S. during the same year was $48,000. A bundle of goods that costs 100 rubies in Ruberia has a price of $1,250 in the U.S

Which country has a higher income per capita using PPP?

If tea and coffee are substitutes, the cross elasticity of coffee with respect to the price of tea will be ________ and an increase in the price of tea will ________ the demand for coffee

A) positive; increase B) negative; decrease C) negative; increase D) positive; decrease