The formula to use for solving simple interest rate problems is:
[tex]i=\text{Prt}[/tex]Where
i is interest accumulated
P is the initial, or principal, amount
r is the rate of interest [in decimal]
t is the time
Given,
Total amount in account is 80 [principal plus interest]
rate is 2%
time is 8 years
Let's write:
[tex]\begin{gathered} 80=P+\text{Prt} \\ 80=P(1+rt) \\ 80=P(1+(0.02)(8)) \\ 80=P(1+0.16) \\ 80=P(1.16) \\ P=\frac{80}{1.16} \\ P=68.9655 \end{gathered}[/tex]The amount in the account was around $68.97
