Question

A bank account balance, b, for an account starting with s dollars, earning an annual interest rate, r, and left untouched for n years can be calculated as Find a bank account balance to the nearest dollar, if the account starts with $200, has an annual rate of 4%, and the money left in the account for 10 years.

Answer 1

well, assuming is "simple interest" rate


`\bf \qquad \textit{Simple Interest Earned Amount}\\\\ A=P(1+rt)\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\to& \$200\\ r=rate\to 4\%\to (4)/(100)\to &0.04\\ t=years\to &10 \end{cases}`

Answer 2

Part A:

As any particular interest is not mentioned, we will calculate the simple interest formula.

`SI=p* r* t`

Now as per given scenario, here p is s.

t is n

So, we can calculate interest as:

`I=s* r* n`

And
`b=s+I`

Part B:

Here p = 200

r = 4% or 0.04

t = 10 years

So, interest is
`200*0.04*10=80` dollars

And amount after 10 years is =
`200+80=280` dollars