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Homework Help: Calculating the island of Manhattan gains after 400 years.

  1. Jun 20, 2011 #1
    According to the legend, the island of Manhattan was purcased from the native indian population in 1626 for 24 dollars. Assuming this money was invested in a Dutch bank paying 5 %
    simple interest per year, costruct a table in C++ showing how much money the native population would have at the end of each 50- year period, starting in 1626 and ending 400 years latter.
    I'm having problems when i try to calculate the total amount of money every 50 year period.
    Thanks in advance.

    2. Relevant equations

    simple Interest = Principal amount * Interest rate * years

    3. The attempt at a solution

    #include <iostream>
    #include <cmath>
    #include <iomanip>

    using namespace std;
    int main ()

    float year;
    double rate, interest, totMoney;

    year = 1626;
    rate = .05;

    cout << " Year Interest gained Total Money" << endl;
    cout << "-----------------------------------------------"<< endl;
    cout << endl;

    while( year <= 2026)

    interest = 24 * .05* 50;
    totMoney = 24 + interest;

    cout << setw(7) << year << setw(15) << interest << setw(15)<< totMoney << endl;

    cout << endl;

    totMoney ++;

    year += 50;


    return 0;
  2. jcsd
  3. Jun 21, 2011 #2


    User Avatar
    Science Advisor

    The basic algorithm looks all right (I'd clean up the output format a little, but that's just me). However, is there a reason you're incrementing totMoney (totMoney++)? Does the legend include a $1 payment every 50 years?

    I'd also suggest using an int for year--you won't have any decimal artifacts in the year field.

    EDIT: And now compare it with compound interest--by 2026, that $24 would have turned into $7,176,800,429.97.
    Last edited: Jun 21, 2011
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