A certain unit wants to send one or several of the three masters Li, Zhang and Wang on a business trip. How many different sending methods are there?
某单位要在李师傅、张师傅和王师傅3人中派出一人或几人出差，共有多少种不同的派出方法．
<gadget id="calculator">3 + 3 + 1</gadget>
<output>7</output>

<result>7</result>