Michelle wants to borrow $4,500. Bank A will lend Michelle the money at a simple annual interest rate of 9% for 6 years. Bank B will lend her the money at 11% for 4 years. Which bank would charge Michelle the least amount of interest? Explain.

1 answer

To determine which bank would charge Michelle the least amount of interest, we will calculate the total interest for both banks using the formula for simple interest:

\[ \text{Interest} = P \times r \times t \]

where:

  • \(P\) is the principal amount (the amount borrowed).
  • \(r\) is the annual interest rate (as a decimal).
  • \(t\) is the time the money is borrowed for (in years).

Bank A:

  • Principal \(P = 4500\)
  • Annual interest rate \(r = 9% = 0.09\)
  • Time \(t = 6\) years

Calculating the interest for Bank A:

\[ \text{Interest} = 4500 \times 0.09 \times 6 \]

\[ \text{Interest} = 4500 \times 0.54 = 2430 \]

Bank B:

  • Principal \(P = 4500\)
  • Annual interest rate \(r = 11% = 0.11\)
  • Time \(t = 4\) years

Calculating the interest for Bank B:

\[ \text{Interest} = 4500 \times 0.11 \times 4 \]

\[ \text{Interest} = 4500 \times 0.44 = 1980 \]

Summary of Interest:

  • Interest charged by Bank A: $2430
  • Interest charged by Bank B: $1980

Conclusion: Bank B would charge Michelle the least amount of interest, totaling $1980, compared to Bank A's total of $2430.