Find how long it takes $500.00 to double if it is invested at 8% compounded semi-annually.

Question

Use A=P(1+r/n)^nt where:

 

A= the amortized amount (total loan/investment amount over the life of the loan/investment)
P= the initial amount of the loan/investment
r= the annual rate of interest
n= the number of times interest is compounded each year
t= the time in years

Find how long it takes $500.00 to double if it is invested at 8% compounded semi-annually.

It will take ______years. (Round answer to 3 decimal places.)

Answer 1

1000=500(1+.08/2)^(2*t)

1000/500=(1.04)^2t

2=(1.04)^(2t)

ln(2)=ln(1.04)^(2t)

ln(2)=2tln(1.04) 

ln(2)/ln(1.04)=2t ------ solve this for 't' and your answer