Question 1204921
A=P*e ^rt

A  is the future value  = 6500

P is the principal =3250

r  the  interest rate =5%

 time   t years = ?

We need to find t 

6500= 3250 *e^(0.05*t)

6500/3250  = e^(0.05t)

2=e^(0.05t)

ln 2= 0.05 t

t= ln 2/0.05

you work out and round it off as required