Sam has $50,000 to invest in ABC company, a stick selling for $80 a share. the initial margin requirement is 60 percent.

a. ignoring traces and commissions, calculate your rates of return uf the stock rises to $100 a share and if it declines to $60 a share assuming you pay cash for the stock.

b. ignoring traces and commissions, calculate your rates of return uf the stock rises to $100 a share and if it declines to $60 a share assuming you buy it using maximum margin.