11) ms. whodunit needs $15 000 to go on her dream vacation in four years. how much does she need to invest now in an account earning 5.5% annual interest compounded semi-annually? [3] 12) after learning about finances in grade 11, you decide to put money and at the end of every month invest $150 into the stock market for the next 48 years (until you retire). assuming the market returns 7% per annum, compounded monthly, how much will you have after 48 years?