When credit terms for a sale are 2/15, n/40, the customer saves by paying early. What percent (rounded) would this savings amount to on an annual basis

As more people migrated west during the gold rush, what do you think happened to the demand curve in most western markets, holding all else constant? a. there was no shift, nor any increase or decrease in quantity demanded. b. there was no shift, but there was a decrease in quantity demanded. c. the demand curve shifted to the left. d. the demand curve shifted to the right. e. there was no shift, but there was an increase in quantity demanded.