Thread: Geometric Series

Josh Deposits $120 at the end of each month into an account that pays 7% interest compounded monthly.After 10 years the balance on his account in dollars is

$\displaystyle 120*((1+(.07/12)^0)+120*((1+(.07/12)^1)+........120*((1+(.07/12))^N)$

A. What Is the First Term? What is R?
B. What is his balance after 10 years?

Originally Posted by Dragon

Josh Deposits $120 at the end of each month into an account that pays 7% interest compounded monthly.After 10 years the balance on his account in dollars is

$\displaystyle 120*((1+(.07/12)^0)+120*((1+(.07/12)^1)+........120*((1+(.07/12))^N)$

A. What Is the First Term? What is R?
B. What is his balance after 10 years?

1) The first term? That makes no sense or is entirely ambiguous. Please object strongly to this question if you have reported it as it was presented. Which term is first? The first deposit? The last deposit?

2) You have parenthesis problems. You mean "[1+(0.07/12)]^2", NOT "1+(0.07/12)^2". Do you see the difference?

3) Why did you stop at "N". You know the number of terms. Fill in the last value. Monthly, 10 years, somewhere around 120? Possibly 119? You tell me.

4) R had better be (1 + 0.07/12).

Can you add up all the terms?