If interest is compounded at 13% per year, how long will it take for 31,000 to

accumulate to 81,000?

Consider the situation where you have worked in a company for 18 years where

you accumulated 4900 shares of company stock. A year ago each share of stock

was worth 31 pesos, so the company has offered to buy back your shares for

200,000 pesos. At what interest rate would the company's offer be equivalent to the

worth of the stock last year?