Question

Charlie invest $425 in a savings account that pays interest at an annual rate of 4% compounded continuously approximately how much time will it take for his investment to double?

Answer 1

Answer:

  17.3 years

Step-by-step explanation:

For some annual interest rate r and time in years t, the initial account value is multiplied by e^(rt).

You want the multiplier e^(.04t) to have a value of 2:

  2 = e^(.04t)

  ln(2) = 0.04t . . . . . take natural logs

  t = ln(2)/0.04 = 17.329 . . . . . divide by the coefficient of t

It will take about 17.3 years for the investment to double.