updated notes

src/rhcsa.md

@@ -388,3 +388,19 @@ until [ $i -gt 10 ]; do
     i=$((i+1))
 done
 ```
+
+### Example script to check a user's age
+```bash
+#!/bin/bash
+echo "Please provide me your age: "
+
+read age
+
+if [ "$age" -le 17 ]; then
+	echo "You cannot enter bars or vote."
+elif [ "$age" -ge 18 ] && [ "$age" -le 20 ]; then
+	echo "You can vote but not enter bars."
+else
+	echo "You are old enough to vote and enter bars."
+fi
+```