Question

Need help with these 2 problems I’m pretty sure I got the first one right but I don’t know how to do the second one please and thank you!!

Answer 1

Since APR interest is a simple interest rate, we are going to use the formula for calculating simple interest:
`A=P(1+rt)`
where

`A` is the final amount after
`t` years

`P` is the initial investment

`r` is the interest rate in decimal form

`t` is the number of years

Mathematical steps for solving the problem:
We can infer from our problem that you are going to invest $800-$640=$160 in your savings account, so
`P=160`. To convert the interest rate to decimal form, we are going to divide the rate by 100%

`r= (4.5)/(100) =0.045`. Since you are leaving the money in your savings account for a year,
`t=1`. Lets replace those values in our formula:

`A=P(1+rt)`

`A=160[1+(0.045)(1)]`

`A=160(1+0.045)`

`A=160(1.045)`

`A=167.2`

We can conclude that your total savings after buying the refurbished laptop are: $167.2