An extreme case where either the quantity demanded (Qd) or supplied (Qs) changes by an infinite amount in response to any change in price is called:

Suppose the government's initial debt is $400 billion. If for the next three years the government runs deficits of $150, $125, and $200 billion, the government's additional debt at the end of the three years will be

A) -$50 billion. B) $50 billion. C) $475 billion. D) $900 billion.

Someone who knows nothing about the relative quality of a $2 toothbrush and a $7 toothbrush, both available for sale, but chooses to buy the more expensive one, is probably

A) displaying an inelastic demand for toothbrushes. B) judging quality by price. C) violating the law of demand. D) wealthy enough not to care about prices.