This question already has an answer here:
Confused by (apparent) inconsistent precision
When I want a numerical value with a precision of 50 digits…
N[1.15/(1 – E^-0.2)^2, 50]
Why is Mathematica not able to provide the desired solution?
And I know that this is irrational and the given solution is not precise and besides Mathematica would provide more digits even if the solution is already precise in other cases.
So what is the problem here and how can I get more digits?
You have to avoid machine numbers. Calculate
(1 + 15/100)/(1 – E^(-(2/10)))^2
and you will get the solution with an ad libitum precision.