Question 630639
How long does it take for $1000 to double if it is invested at 3% interest compounded monthly? 
{{{A = P(1 + i/n)^(nt)}}}
{{{2000 = 1000(1 + .03/12)^(12t)}}}
{{{2 = (1 + .03/12)^(12t)}}}
{{{2 = (1.0025)^(12t)}}}
{{{log(1.0025,2) = 12t}}}
{{{log(2)/log(1.0025) = 12t}}}
{{{log(2)/(12*log(1.0025)) = 12t}}}
{{{23.1 = t}}}
.
That's ~23 years