An article has 30 lines, 20 characters per line. It took Lingling 10 minutes to type this article. How many words per minute does she type on average?
一篇文章有30行，每行20个字，玲玲花了10分钟打完了这篇文章，她平均每分钟打几个字？
<gadget id="calculator">20 / 10</gadget>
<output>2</output>

<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<result>60</result>