Let x be the amount the woman invests in the 15% bond, then the amount she invested in her CD is given by $60,000 - x.
The interest she receives from the 15% bond is given by 0.15x while the interest she receives from the 7% CD is given by 0.07(60,000 - x) = 4,200 - 0.07x
Giving that her total annual interest is $6,000, then
[tex]0.15x+4,200-0.07x=6,000 \\ \\ \Rightarrow0.08x=6,000-4,800=1,200 \\ \\ \Rightarrow x= \frac{1,200}{0.08} =$15,000[/tex]
Therefore, the amount of dollars she will be able to invest in her CD is $60,000 - $15,000 = $45,000
