SOLUTION: How long will it take to double your money if you invest it at a rate of 8% compounded annually? Thank you!!

Algebra ->  Finance -> SOLUTION: How long will it take to double your money if you invest it at a rate of 8% compounded annually? Thank you!!      Log On


   

Question 1077372: How long will it take to double your money if you invest it at a rate of 8% compounded annually?
Thank you!!
Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!
F+=+P%281%2Br%2Fn%29%5E%28nt%29+
n = number of payments per year
r = interest rate per year, expressed as a decimal
P = present value
F = future value
t = time, in units of years
This problem has: t=unknown, F=2P, r=0.08, n=1
F+=+2P+=+P%281%2B0.08%29%5E%28t%29+
+++++2+=+%281.08%29%5Et+
++ln%282%29+=+t%2Aln%281.08%29+ <— key step, take ln() of both sides, +ln%28a%5Eb%29+=+b%2Aln%28a%29+
+++ln%282%29%2Fln%281.08%29+=+t+
+++highlight%28t+=+9.00years%29+