Betsy, a recent retiree, requires 5,000 per year in extra income. she has $70,000 to invest and can invest in b rated bonds paying 13% per year or in a certificate of deposit (cd) paying 5% per year. how much should be invested in each to realize exactly $5,000 in interest per year?

B = amount invested in B bonds

c = amount invested in CDs

so.. she's got $70000 burning a hole in her pocket and she wants to invest them to get a yield of 5000 in interest from both of them.

we know that, whatever "c" and "b" are, we  know that b + c = 70,000.

how much is 13% of b? well, (13/100) * b, or 0.13b
how much is 5% of c?  well, (5/100) * a, or 0.05c

we know that, the yield or interest earned from them, must be 5000, thus 0.13b + 0.05c = 5000.



how much did she invest in CDs?  well, c = 70000 - b.

Where is your question?

The answer is 16.64 feetyour welcome