Aerial's grandmother gave her $5,500.00 to save for her college education. She went to the bank to open a savings account. The bank told her they had two options available.

Account A will pay 5.5% simple interest until the account is closed.

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. When the initial account is closed, the bonus account will be closed as well and the money from the two accounts will be combined.

If Aerial is planning on leaving the money in the account for 4 years and then withdrawing all funds, then account
is the better choice earning her
more.

User Icon for Bot GPT 4-o mini Bot GPT 4-o mini answered
6 hours ago

To determine which account Aerial should choose, we will calculate the total amount she would have in each account after 4 years.

Account A:

Account A pays 5.5% simple interest.

The formula for simple interest is: \[ \text{Total Amount} = \text{Principal} + (\text{Principal} \times \text{Rate} \times \text{Time}) \]

Calculation for Account A:

  • Principal: \( P = 5500 \)
  • Rate: \( r = 5.5% = 0.055 \)
  • Time: \( t = 4 \) years

\[ \text{Total Amount} = 5500 + (5500 \times 0.055 \times 4) \]

Calculating the interest: \[ \text{Interest} = 5500 \times 0.055 \times 4 = 5500 \times 0.22 = 1210 \]

Now adding the interest to the principal: \[ \text{Total Amount} = 5500 + 1210 = 6710 \]

Account B:

Account B pays 4.5% simple interest for 3 years and then opens a bonus account with $250.

Calculation for the initial account (first 3 years):

  • Rate: \( r = 4.5% = 0.045 \)
  • Time: \( t = 3 \) years

\[ \text{Total Amount (Year 3)} = 5500 + (5500 \times 0.045 \times 3) \]

Calculating the interest for the first 3 years: \[ \text{Interest} = 5500 \times 0.045 \times 3 = 5500 \times 0.135 = 742.5 \]

Adding this interest: \[ \text{Total Amount (Year 3)} = 5500 + 742.5 = 6242.5 \]

Now, at the end of year 3, a bonus account of $250 is opened that earns 4.5% for 1 more year.

Calculation for the bonus account for 1 additional year (from Year 3 to Year 4):

  • Principal for the bonus account: \( 250 \)
  • Rate: \( 0.045 \)
  • Time: \( t = 1 \) year

Calculating interest for the bonus account: \[ \text{Interest (Bonus Account)} = 250 \times 0.045 \times 1 = 11.25 \]

Adding this to the bonus account: \[ \text{Total in Bonus Account} = 250 + 11.25 = 261.25 \]

Now, adding the total from the initial account (after 4 years) and the bonus amount: \[ \text{Total Amount (after 4 years)} = 6242.5 + 261.25 = 6503.75 \]

Conclusion:

  • Total from Account A = $6710
  • Total from Account B = $6503.75

Thus, Account A is the better choice, earning her $206.25 more than Account B.