Question

How long would it take to double an investment of $1000 if it is invested at 3.5%, compounded continuously?

Answer 1

Solve 1000*1.035^n = 2000
...
which simplifies to 1.035^n = 2

Answer 2

You know how to solve that? Use log's.

Answer 3

what formula of logs would be used?

Answer 4

Take the log of both sides, first to get
log(1.035^n) = log(2)
Then use the fact that log(a^b) = b*log(a)...
n*log(1.035) = log(2)
n = log(2) / log(1.035) =_________