Which of these can be represented by the expression

?

A.
the balance of a savings account after t years if the initial balance is $500 and it is invested at a 3.5% annual interest rate compounded annually

B.
the balance of a savings account after t years if the initial balance is $500 and it is invested at a 0.875% annual interest rate compounded annually

C.
the balance of a savings account after t years if the initial balance is $500 and it is invested at a 0.875% annual interest rate compounded quarterly

D.
the balance of a savings account after t years if the initial balance is $500 and it is invested at a 3.5% annual interest rate compounded quarterly

3 answers

To determine which options can be represented by the expression \( A = P(1 + r/n)^{nt} \), where:

  • \( A \) is the amount of money accumulated after n years, including interest.
  • \( P \) is the principal amount (the initial balance).
  • \( r \) is the annual interest rate (decimal).
  • \( n \) is the number of times that interest is compounded per year.
  • \( t \) is the number of years the money is invested or borrowed.

Let's analyze each option:

A. The balance of a savings account after \( t \) years if the initial balance is $500 and it is invested at a 3.5% annual interest rate compounded annually.

  • Here, \( P = 500 \), \( r = 0.035 \), \( n = 1 \) (compounded once a year).
  • This can be represented as: \[ A = 500(1 + 0.035/1)^{1 \cdot t} \]

B. The balance of a savings account after \( t \) years if the initial balance is $500 and it is invested at a 0.875% annual interest rate compounded annually.

  • Here, \( P = 500 \), \( r = 0.00875 \), \( n = 1 \).
  • This can be represented as: \[ A = 500(1 + 0.00875/1)^{1 \cdot t} \]

C. The balance of a savings account after \( t \) years if the initial balance is $500 and it is invested at a 0.875% annual interest rate compounded quarterly.

  • Here, \( P = 500 \), \( r = 0.00875 \), \( n = 4 \) (because it is compounded quarterly).
  • This can be represented as: \[ A = 500(1 + 0.00875/4)^{4t} \]

D. The balance of a savings account after \( t \) years if the initial balance is $500 and it is invested at a 3.5% annual interest rate compounded quarterly.

  • Here, \( P = 500 \), \( r = 0.035 \), \( n = 4 \).
  • This can be represented as: \[ A = 500(1 + 0.035/4)^{4t} \]

Based on the analysis:

  • Option A can be represented by the formula.
  • Option B can be represented by the formula.
  • Option C can be represented by the formula.
  • Option D can be represented by the formula.

Thus, all four options (A, B, C, and D) can be represented by the expression given.

choose one answer

Given the requirement to choose just one answer based on the provided expression \( A = P(1 + r/n)^{nt} \) for different scenarios, the most straightforward representation is:

A. the balance of a savings account after \( t \) years if the initial balance is $500 and it is invested at a 3.5% annual interest rate compounded annually.

This option represents the simplest case where interest is compounded annually (\( n = 1 \)), making it the clearest fit for the expression.