Hello, Mariana!

These involve an Annuity and then Compound Interest.

. . . . . . . . . . . . . . . . . . .(1 + i)^n - 1You save $20 000 in a savings account at the end of each year for 9 years.

The annual interest rate is 3%.

a) How much is the total amount immediately after the last deposit?

Annuity formula: . A .= .D ---------------

. . . . . . . . . . . . . . . . . . . . . . i

where D = periodic deposit

. . . . . i = periodic interest rate

. . . . .n = number of periods

. . . . .A = final amount

We have: D = 20,000, i = 0.03, n = 9

. . . . . . . . . . . . . . . . . . 1.03^9 - 1

Therefore: . A .= .20,000 ------------- . ≈ . $203,182.12

. . . . . . . . . . . . . . . . . . . . 0.03

We deposit K dollars each year for 9 years at 3%b) You save an amount K on a savings account at the end of each year for 9 years.

The annual interest rate is 3%.

How much is the total amount 5 years after the last deposit?

. . . . . . . . . . . . . . . . . . . . . . 1.03^9 - 1

At the end of 9 years: . A .= .K ------------- .≈ .10.1591K

. . . . . . . . . . . . . . . . . . . . . . . . 0.03

This amount is left in the account for another 5 years.

. . Its value will be: .10.1581K (1.03)^5 .≈ .11.776K

If the above value is $300,000: .11.776K .= .300,000 . → . K .≈ .$25,475.54c) How much is the yearly savings amount if the total amount 5 years

after the last deposit is $300 000?

Drat . . . The deposits are made at theendof each year.

Are all my answers wrong?

If they are, would someone correct them . . .please?