Question

I'm trying to make this C++ loan calculator but I can't get the program to output what I need. For instance I know the formula is right and when I enter 100000 1.5 20 as my cin variables I should get 482.55 but I get 1543.31. What am I not seeing as the issue? Also this should cout only 2 decimal places right? I'm not allowed to alter the #include and add any fixed setprecision.

This is what I have.

#include <iostream>
#include <cmath>
using namespace std;

int main() {
   // ---------------- Add code here --------------------
   // -- Declare necessary variables here              --
  
    int years = 0;
    int LoanAmount = 0;
    double AnnualRate = 0.0;
    double moPayment = 0.00;
  
    // --
    cout << "Enter the amount, rate as a percentage (e.g. 3.25), and number of years\n";
    cout << " separated by spaces: " << endl;

   // ---------------- Add code here --------------------
   // -- Receive input and compute the monthly payment --
   cin >> LoanAmount >> AnnualRate >> years;

   AnnualRate = AnnualRate / 100;    //rate to decimal
   years = years * 12;   //years to months

   moPayment = (LoanAmount * AnnualRate) / (1 - pow(1 + AnnualRate, -years));
  
   // ---------------- Add code here ------------------
    // Print out the answer as a double, all by itself
    // (no text) followed by a newline
    // Ex. cout << payment << endl;

   cout << moPayment << endl;

  
    return 0;
}

Answer 1

#include <iostream>

#include <cmath>

using namespace std;

int main() {

       // ---------------- Add code here --------------------

       // -- Declare necessary variables here              --

       int years = 0;

       int LoanAmount = 0;

       double AnnualRate = 0.0;

       double moPayment = 0.00;

       // --

       cout << "Enter the amount, rate as a percentage (e.g. 3.25), and number of years\n";

       cout << " separated by spaces: " << endl;

       // ---------------- Add code here --------------------

       // -- Receive input and compute the monthly payment --

       cin >> LoanAmount >> AnnualRate >> years;

       double MonthlyRate = AnnualRate / 1200;    //get the monthly rate to decimal

       years = years * 12;   //years to months

       // for monthly payment, monthly rate is required not Annual Rate

       moPayment = (LoanAmount * MonthlyRate) / (1 - pow(1 + MonthlyRate, -years));

       moPayment = round(moPayment*100)/100; // round the result to 2 decimal places

       // ---------------- Add code here ------------------

       // Print out the answer as a double, all by itself

       // (no text) followed by a newline

       // Ex. cout << payment << endl;

       cout << moPayment << endl;

       return 0;

}

//end of program

Output: