Exponential Equations

Question

Find the time it takes for $6,700 to double when invested at an annual interest rate of 18%, compounded continuously.
____________________years  

Find the time it takes for $670,000 to double when invested at an annual interest rate of 18%, compounded continuously.
 ______________________years

 

 

give answer accurate to 4 decimal places

Answer 1

A = Pe^rt, where P = principal, A = amount, r is rate in decimals, t is time in years.  

Fill in formula:

 

13400 = 6700e^.18t

 

2 = e^.18t

 

ln2 = .18t

 

t = 3.85 years

 

You do the second part.