What is the total amount in an account that has had $35 per month added into it for 30 years and grew with an annual interest rate of 7%

The Future Value of an Annuity is given by:

FV = P [(1 + r)ⁿ - 1] / [r].........where

P = periodic payment..... ($35)

n = number of periods......(360)

r = rate per period = (.07/12) = 0.0058333333333333

So we have......

35 [(1 + 0.0058333333333333)³⁶⁰ - 1)] / (0.0058333333333333) ≈ $42698.98

Let me try.

$35*12=$420

$420*30=$12,600

$12,600*7%=$882

I don't know if the question asks for tha annual rate of 7% per year or what. If it is for 1 year, the answer is right below.

$882

$12,600-$882=$11,718

So, the answer is $11,718.

Hope it helps!

I tried my best. Don't give me negative points, please.

DragonSlayer. Good Try, I see what you did. But you seemed to have calculated this as Simple Interest. For this question, you need to solve it as Compound Interest. Lets start.

Let me first introduce you to the Compound Interest Formula.

Principal X (1 + Periodic Rate) ^ Number of Periods = Future Amount

Principal is the amount in the account in one yeat given that this is an annual interest.

So lets add the Principal:

$${\mathtt{35}}{\mathtt{\,\times\,}}{\mathtt{12}} = {\mathtt{420}}$$

The Principal is 420.

So lets add that in:

420 * (1 + Period rate) ^ Number of Periods. = Future Amount.

Now the period rate is 7%. So lets turn that into a decimal.

0.07. Lets place that in

420 * (1 + 0.07) ^ Number of Periods. = Future Amount.

Number of Periods is the Year.

420 * (1 + 0.07) ^ 30= Future Amount.

$${\mathtt{420}}{\mathtt{\,\times\,}}{\left({\mathtt{1}}{\mathtt{\,\small\textbf+\,}}{\mathtt{0.07}}\right)}^{{\mathtt{30}}} = {\mathtt{3\,197.147\: \!117\: \!918\: \!052\: \!266\: \!8}}$$

The amount would then be 3,197.14 Dollars.

However, providing that Money is deposited every month... I will solve it on the next post.

CPhill and  TakahiroMaeda, can you please help me on this math question? Can you explain it a little further? Please CPhill and TakahiroMaeda?

Awkward moment when there are two answers. And the feeling that you got it wrong.

I think I got it wrong ._.

Me too. I think I got it wrong too.

When all else fails....rely on CPhill!