$23970.00 dollars is invested at 5.0% using simple interest. If the future value is $31161.00, how long was it invested? Round to the nearest tenth of a year.

Using $LaTeX: \displaystyle FV = PV +PVrt \iff FV - PV = PVrt \iff t = \frac{FV - PV}{PVr}$ . Evaluating gives $LaTeX: \displaystyle t = \frac{31161.0-23970}{(23970)(0.050)} = 6.0$ years