Jill invested $500 in an account with a compound interest rate of 6%. Cheryl invests $600 in an account with a compound interest rate of 4%.Find out in how many years each doubles her money. Using the rule of 72, , what is the difference in the number of years to double their money?

Leading guitar string producer wound up inc. has enjoyed a competitive advantage based on its proprietary coating that gives its strings a clearer sound and longer lifespan than uncoated strings. one of wound up's competitors, however, has recently developed a similar coating using less expensive ingredients, which allows it to charge a lower price than wound up for similar-quality strings. wound up's competitive advantage is in danger due to a. a lack of perceived value b. a lack of organization c. direct imitation and substitution d. resource immobility