Question
A high school student deposits their summer job earnings of $800 into a simple interest savings plan with a %15 rate. How much will the student have earned after 4 years?
Answers
GPT-4o mini
To calculate the earnings from a simple interest savings plan, you can use the formula:
\[
\text{Interest} = P \times r \times t
\]
where:
- \( P \) is the principal amount (initial deposit),
- \( r \) is the annual interest rate (as a decimal),
- \( t \) is the time in years.
In this case:
- \( P = 800 \) (the amount deposited),
- \( r = 0.15 \) (the interest rate of 15% expressed as a decimal),
- \( t = 4 \) (the number of years the money is invested).
Plug these values into the formula:
\[
\text{Interest} = 800 \times 0.15 \times 4
\]
\[
\text{Interest} = 800 \times 0.15 = 120
\]
\[
\text{Interest} = 120 \times 4 = 480
\]
After 4 years, the student will have earned **$480** in interest.
To find the total amount in the account after 4 years, add the earned interest to the principal:
\[
\text{Total Amount} = P + \text{Interest} = 800 + 480 = 1280
\]
Thus, the student will have a total of **$1280** in the account after 4 years.
\[
\text{Interest} = P \times r \times t
\]
where:
- \( P \) is the principal amount (initial deposit),
- \( r \) is the annual interest rate (as a decimal),
- \( t \) is the time in years.
In this case:
- \( P = 800 \) (the amount deposited),
- \( r = 0.15 \) (the interest rate of 15% expressed as a decimal),
- \( t = 4 \) (the number of years the money is invested).
Plug these values into the formula:
\[
\text{Interest} = 800 \times 0.15 \times 4
\]
\[
\text{Interest} = 800 \times 0.15 = 120
\]
\[
\text{Interest} = 120 \times 4 = 480
\]
After 4 years, the student will have earned **$480** in interest.
To find the total amount in the account after 4 years, add the earned interest to the principal:
\[
\text{Total Amount} = P + \text{Interest} = 800 + 480 = 1280
\]
Thus, the student will have a total of **$1280** in the account after 4 years.