Question

You have money in an account at 6% interest, compounded monthly. To the nearest year, how long

will it take for your money to double.

Answer 1

Explanation:

Let amount now be x , meaning principal is x

and the amount later A is 2x

A = P(1+r/n)^nt

n = 12

2x = x (1 + 0.06/12)^12t

divide through by x

2 = (1+ 0.005)^12t

2 = (1.005)^12t

Take log of both sides

log 2 = 12t log 1.005

12t = log2/log 1.005

12t = 138.975721610697

t = 138.975721610697/12

t = 11.58

t = 12 years