How to create a while loop that can determine how many years do you have to invest $100000 at a compound interest of 5% per year to double your money?

I need help basically doing the same thing in the picture I have attached but using a while loop.

Answer 1

[KSSV]

Amount = 100000 ;
Amount0 = Amount ;

yr = 0 ;
while Amount <= 2*Amount0
    yr = yr+1 ;
    Amount = Amount*1.05 ;
    fprintf('Amount at year %d is %.2f\n',yr,Amount)
end

Answer 2

[Image Analyst]

Try this

Amount = 100000
numYears = 0;
while Amount < 200000
    Amount = Amount * 1.05
    numYears = numYears + 1;
    fprintf('After %d years, the Amount = %.2f\n', numYears, Amount);
end

Answer 3

[Roger Stafford]

Who needs a loop to do this trivial problem? We want to solve for n in the equation

   100000*(1.05)^n = 200000

Rewrite it as

   n*log(1.05) = log(2)
   n = log(2)/log(1.05)

Matlab version:

   n = ceil(log(2)/log(1.05));

[Steven Lord]

 Who needs a loop to do this trivial problem?

The student whose professor assigned them this homework to teach them how to use while loops and insists they use a while loop to solve it. :)

[Roger Stafford]

Yes, Steven, you are right. However, I wish those same professors would choose problems using while loops that were not so easy to do in one’s head. That way the student might be more motivated to making good use of a while loop where it was apparent that it would be difficult to do without it.