betsy, a recent retiree, requires $6,000 per year in extra income. she has $70,000 to invest and can invest in b-rated bonds paying 15% per year or in a certificate of deposit (cd) paying 5% per year. how much money should be invested in each to realize exactly $6 comma 000 in interest per year? the amount of money invested at 15 % equals $ the amount of money invested at 5% equals