Hong Hong typed 252 characters in 6 minutes, and Lin Lin typed 220 characters in 4 minutes. Who is faster? How many words are typed per minute?
红红6分钟打了252个字，林林4分钟打了220个字．谁打得快？每分钟多打多少个字？
<gadget id="calculator">220 / 4</gadget>
<output>55</output>

<gadget id="calculator">252 / 6</gadget>
<output>42</output>

<gadget id="calculator">55 - 42</gadget>
<output>13</output>

<result>13</result>