10. Program where you tell the final amount and it figures out how many years it will take, at a fixed rate of interest compounded yearly, to reach this amount.

Chapter 3: 

Loops and Decisions

Programming Exercise

Problem # 10:

Write another version of the program from Exercise 7 so that, instead of finding the final amount of your investment, you tell the program the final amount and it figures out how many years it will take, at a fixed rate of interest compounded yearly, to reach this amount. What sort of loop is appropriate for this problem? (Don’t worry about fractional years; use an integer value for the year.)

Solution:

#include<iostream>
using namespace std;
int main()
{
    int years=0;
    float rate, amount, total;
  
    cout<<"Enter initial amount: ";
    cin>>amount;
    cout<<"Enter final amount: ";
    cin>>total;
    cout<<"Enter interest rate (percent per year): ";
    cin>>rate;
    rate=rate/100;
  
    while(total>=amount)
    {
        amount=amount + (amount * rate);
        years++;
    }
  
    cout<<"At the end of "<<years<<" years you will have "<<total<<" dollars";
  
    return 0;
}

Let me know in the comment section if you have any question.

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