Question 1104551
P=Po(1+r/2)^2t, t is years
Any amount to double is where P=2Po
so 2=(1+0.035)^2t
ln2=2t ln(1.035)
2t=ln 2/ln (1.035)
t=10.07 years
as a rough check, the rule of 72 would predict 10.29 years.