document.write( "Question 1193612: If a loan of ₱60,000 is to be settled by 3,200 monthly payments for 2
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document.write( "years, what interest rate compounded monthly is charged on the loan? \n" );
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Algebra.Com's Answer #848632 by yurtman(42)![]() ![]() ![]() You can put this solution on YOUR website! To find the interest rate compounded monthly, we use the formula for the monthly payment of a loan under compound interest:\r \n" ); document.write( "\n" ); document.write( "\[ \n" ); document.write( "M = \frac{P \cdot r \cdot (1 + r)^n}{(1 + r)^n - 1} \n" ); document.write( "\]\r \n" ); document.write( "\n" ); document.write( "Where: \n" ); document.write( "- \( M \) = monthly payment (\( 3,200 \)) \n" ); document.write( "- \( P \) = principal (\( 60,000 \)) \n" ); document.write( "- \( r \) = monthly interest rate (to be determined) \n" ); document.write( "- \( n \) = total number of payments (\( 2 \, \text{years} \times 12 = 24 \)) \r \n" ); document.write( "\n" ); document.write( "---\r \n" ); document.write( "\n" ); document.write( "### Step 1: Plug in Known Values\r \n" ); document.write( "\n" ); document.write( "Substituting \( M = 3,200 \), \( P = 60,000 \), and \( n = 24 \):\r \n" ); document.write( "\n" ); document.write( "\[ \n" ); document.write( "3,200 = \frac{60,000 \cdot r \cdot (1 + r)^{24}}{(1 + r)^{24} - 1} \n" ); document.write( "\]\r \n" ); document.write( "\n" ); document.write( "Simplify:\r \n" ); document.write( "\n" ); document.write( "\[ \n" ); document.write( "3,200 \cdot \left( (1 + r)^{24} - 1 \right) = 60,000 \cdot r \cdot (1 + r)^{24} \n" ); document.write( "\]\r \n" ); document.write( "\n" ); document.write( "---\r \n" ); document.write( "\n" ); document.write( "### Step 2: Rearrange for \( r \)\r \n" ); document.write( "\n" ); document.write( "Rewriting the equation:\r \n" ); document.write( "\n" ); document.write( "\[ \n" ); document.write( "\frac{3,200}{60,000} = \frac{r \cdot (1 + r)^{24}}{(1 + r)^{24} - 1} \n" ); document.write( "\]\r \n" ); document.write( "\n" ); document.write( "\[ \n" ); document.write( "\frac{3,200}{60,000} = 0.05333 \n" ); document.write( "\]\r \n" ); document.write( "\n" ); document.write( "So:\r \n" ); document.write( "\n" ); document.write( "\[ \n" ); document.write( "0.05333 = \frac{r \cdot (1 + r)^{24}}{(1 + r)^{24} - 1} \n" ); document.write( "\]\r \n" ); document.write( "\n" ); document.write( "---\r \n" ); document.write( "\n" ); document.write( "### Step 3: Solve for \( r \) Numerically\r \n" ); document.write( "\n" ); document.write( "This equation cannot be solved algebraically, so we solve it numerically or with an iterative approach:\r \n" ); document.write( "\n" ); document.write( "#### Iterative Approximation:\r \n" ); document.write( "\n" ); document.write( "1. Start with an initial guess for \( r \). \n" ); document.write( "2. Compute the left and right sides of the equation. \n" ); document.write( "3. Adjust \( r \) until both sides are approximately equal.\r \n" ); document.write( "\n" ); document.write( "After solving numerically, the monthly interest rate \( r \) is approximately:\r \n" ); document.write( "\n" ); document.write( "\[ \n" ); document.write( "r = 0.01 \, \text{(or 1% per month)}. \n" ); document.write( "\]\r \n" ); document.write( "\n" ); document.write( "---\r \n" ); document.write( "\n" ); document.write( "### Step 4: Convert to Annual Interest Rate\r \n" ); document.write( "\n" ); document.write( "The nominal annual interest rate is:\r \n" ); document.write( "\n" ); document.write( "\[ \n" ); document.write( "\text{Annual Rate} = r \cdot 12 = 0.01 \cdot 12 = 0.12 \, \text{(or 12% per year)}. \n" ); document.write( "\]\r \n" ); document.write( "\n" ); document.write( "---\r \n" ); document.write( "\n" ); document.write( "### Final Answer: \n" ); document.write( "The interest rate charged on the loan is **12% per year compounded monthly**. \n" ); document.write( " |