Question 1055166
 In General {{{A(t) = P(1+r/n)^(nt)}}}
A = Accumulated Amount
P= principal = 
r= annual rate = .
n= periods per year = 
t= years =
{{{A(t)/P = (1+r/4)^(4*5)}}}
{{{12000/10000 = (1+r/4)^(20)}}}
1.2 = {{{(1+r/4)^(20)}}}
{{{root(20,1.2) = 1 + r/4}}}
{{{4(root(20,1.2)-1) =r}}}