Simple Mathematics

£5 is deposited into a bank account. At 6% interest every year, how many years will it take to exceed £200?

It would be nice to confirm if
5*(1.06)^64=£208.23
is the correct answer.
If a geometric series is used and n>1+((log(200/5)/(log(106%)), would it also be 64 years, or 65?

You don't need to add 1 in the inequality, just take the next higher integer.  So take the next integer higher than log(200/5)/log(1.06)=63.307852.