Suppose the demand for pens increases and the supply for pens decreases. What effect will it have on the equilibrium price for pens?

Consider a demand curve that has a constant elasticity value of 0. What happens to quantity demanded and total revenue when price increases?

A) The quantity demanded and total revenue remain the same. B) The quantity demanded does not change but total revenue increases. C) The quantity demanded and total revenue fall to zero. D) The quantity demanded does not change but total revenue decreases.

Refer to the figure in which S is the before-tax supply curve and S t is the supply curve after an excise tax is imposed. The burden of this tax is borne:

A.  equally by consumers and producers.
B.  most heavily by consumers.
C.  most heavily by producers.
D.  only by consumers.