Answer:
Account B is the better choice for earning her (6751.25 - 6710) = $41.25 more.
Step-by-step explanation:
Account A will pay 5.5% simple interest until the account is paid.
Therefore, after 4 years the principal $5500 will grow up to [tex]5500( 1 + \frac{5.5 \times 4}{100} ) = 6710[/tex] dollars.
Now, Account B will pay 4.5% simple interest and if the account is left open for longer than 3 years, then at the end of the third year a bonus account will be opened with $250 that also earns 4.5% for the remainder of the time the initial account is open.
Therefore, after 4 years the principal $5500 will grow with a simple interest of 4.5% and the bonus $250 will earn the same rate of simple interest for 1 year.
Hence, the total sum will become [tex]5500(1 + \frac{4.5 \times 4}{100}) + 250( 1 + \frac{4.5}{100}) = 6490 + 261.25 = 6751.25[/tex] dollars.
Therefore, account B is the better choice for earning her (6751.25 - 6710) = $41.25 more. (Answer)