Helen recently received a credit card with a nominal interest rate of 21 percent. With the card, she purchased some new clothes for $250. The minimum payment on the card is only $20 per month. If Helen makes the minimum monthly payment and makes no other charges, how long will it be before she pays off the card?

Suppose that two countries, britain and the u.s. produce just one good - beef. suppose that the price of beef in the u.s. is $2.80 per pound, and in britain it is £3.70 per pound. according to ppp theory, what should the $/£ spot exchange rate be? suppose the price of beef is expected to rise to $3.10 in the u.s. and to £4.65 in britain. what should be the one year forward $/£ exchange rate?