Group value in range r
<p>I have my table(input)</p>

<pre><code>name   value
Rob    35
Helen  20
Sergey 16
Linn   40
Elena  23
Mary   40
</code></pre>

<p>And I want to count how many of my users is in custom range (0-20,21-30,>30)(output):</p>

<pre><code>range  num
0-20   2
21-30  1
30-    3 
</code></pre>

<p>THX! Sorry if this theme not new, but I can't find answer!</p>