Harmonic series/Finite/Exceeding/Exercise

Let

${}x_{n}:=\sum _{k=1}^{n}{\frac {1}{k}}\,.$

1. Find the smallest ${}n$ such that

   ${}x_{n}\geq 2\,.$

2. Find the smallest ${}n$ such that

   ${}x_{n}\geq 2{,}5\,.$

Create a solution