Answer:
$307.5.
Step-by-step explanation:
We have been given that Elena's aunt bought her a $150 savings bond when she was born.When Elena is 20 years old, the bond will have earned 105% in interest.
To find bond's value after 20 years we will add 105% of 150 to 150.
[tex]\text{Bond's value after 20 years}=150+(\frac{105}{100}\times 150)[/tex]
[tex]\text{Bond's value after 20 years}=150+(1.05\times 150)[/tex]
[tex]\text{Bond's value after 20 years}=150+157.5[/tex]
[tex]\text{Bond's value after 20 years}=307.5[/tex]
Therefore, the bond will be worth $307.5, when Elena will be 20 years old.