document.write( "Question 849282: BofA offer two programs for a car loan, 1st program offer is based on simple interest of 6.8% for four years. The 2nd program is based on a compound monthly with interest rate of 5.5% for four years. Joan is considering to borrow $12,500 to buy a car and ask your opinion for the loan. Which loan would you suggest to her and why. How much interest she will pay on both loans after 32 months? \n" ); document.write( "
Algebra.Com's Answer #511483 by Theo(13342)\"\" \"About 
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Simple Interest Loan:\r
\n" ); document.write( "\n" ); document.write( "I = P * R * T\r
\n" ); document.write( "\n" ); document.write( "I = interest
\n" ); document.write( "P = principal
\n" ); document.write( "R = Interest Rate per Time Period
\n" ); document.write( "T = Number of Time Periods\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "In your problem:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "P = 12,500
\n" ); document.write( "R = .068 per year.
\n" ); document.write( "T = 4 years
\n" ); document.write( "I = Interest\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Replace P with 12,500 and R with .068 and T with 4 and the simple interest formula becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I = 12,500 * .068 * 4 = $3,400.\r
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\n" ); document.write( "\n" ); document.write( "Compound Interest Loan:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "F = P * (1+R)^T
\n" ); document.write( "I = F - P\r
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\n" ); document.write( "\n" ); document.write( "Combine these formulas together and you get:\r
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\n" ); document.write( "\n" ); document.write( "I = P * (1+R)^T - P\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Simplify this formula further using the distributive law and you get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I = P * ((1+R)^T - 1)\r
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\n" ); document.write( "\n" ); document.write( "You can use the formula in either form to get your answer.\r
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\n" ); document.write( "\n" ); document.write( "The forms are:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "F = P * (1+R)^T
\n" ); document.write( "I = F - P\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I = P * (1+R)^T - P\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I = P * ((1+R)^T - 1)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I used the first form which calculates the future value of the loan first and then calculates the interest by subtracting the principal.\r
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\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "F = Future Value of the loan which is the amount you have to pay back at maturity.
\n" ); document.write( "P = Principal or what is also known as the Present Value of the loan.
\n" ); document.write( "R = Interest Rate per Time Period
\n" ); document.write( "T = Number of Time Periods.
\n" ); document.write( "I = Interest\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "In your problem:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "P = 12,500
\n" ); document.write( "R = .055 per year divided by 12 months = .00458333 per month.
\n" ); document.write( "T = 4 years * 12 compounding periods per year = 48 months.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Replace P with 12,500 and R with .00458333 and T with 48 and the compound interest formula becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "F = 12,500 * (1.0094583)^48 = $15,568.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Replace F with 15,568 and the I = F - P formula becomes:\r
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\n" ); document.write( "\n" ); document.write( "I = 15,568 - 12,500 = $3,068.\r
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\n" ); document.write( "\n" ); document.write( "She should take the second loan because she will pay over $300.00 less in interest over the 4 year period.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "After 32 months, the interest on the simple interest loan will be equal to:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I = P * R * T = 12,500 * l068 * (32/12) = $2,266.67\r
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\n" ); document.write( "\n" ); document.write( "Since T is in years, you need to divide 32 by 12 to get the equivalent number of years.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "After 32 months, the interest on the compound interest loan will be equal to:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "F = P * (1 + R) ^ T = 12,500 * (1.004583333) ^ 32 = 14,469.75 - 12,500 = $1,969.75\r
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\n" ); document.write( "\n" ); document.write( "With simple interest, you can calculate the interest directly.
\n" ); document.write( "With compound interest, you have to calculate the future value of the loan and then subtract the principal from that to get the interest.\r
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