Search Second Column for Characters

How to search the second column for string starting with.

Here are the contents of results.txt.

<pre lang="bash">
John 10
Mario 12
Derek 15
Mark 20
Matt 25

Display only individuals that are older than 20 using awk.

<pre lang="bash">
awk '$2 ~ /^20/' results.txt

Result.

<pre lang="bash">
Mark 20
Matt 25

You can easily adjust this to other columns.