Thread: What to do with this geometric problem

Please help me with a) and b). I have tried everything but cannot get the answer $12,351.86 for a). What formula do we use to solve for a)? Please help me on this.

(a)

I guess there is a more pretty way to write this?

The algorithm below does what it says in the question. You put 500$ a month, next time you put money it has passed a month, the account change, so you update the account with the compounded interest before you add the 500.
the time(t)=1/12, and r=0.03

...repeat for all the months.

formula:
f(t) = Pe^tr
Continuously Compounded Interest Formula and Calculator

algorithm:

Code:

var months = 24;
var rate = 0.03;
var deposite = 500;
var account = 500;

i=1;
while(i<months)
{
	account = account*(Math.pow(Math.E,((1/12)*rate)));
	account +=deposite;
	trace(account);
	i++;
}

Code:

1001.2515638028976
1503.7578242325983
2007.5219219548653
2512.5470054969496
3018.836231267267
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4035.219774650508
4545.3204446638865
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6083.296329561952
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8151.956396051423
8672.361783147619
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10241.40684184946
10767.042390037474
11293.993671076743
11822.263978414492
12351.85661374186