The master and the apprentice process the same number of parts. When the master completes the task, the apprentice still has 30 unfinished parts;
师徒二人加工同样多的零件，当师傅完成任务时，徒弟还剩下30个没完成；当徒弟完成任务时，师傅超出任务50个，问师、徒的任务一共是多少个．
<gadget id="calculator">50 * 30</gadget>
<output>1_500</output>

<gadget id="calculator">50 - 1 - 30</gadget>
<output>19</output>

<gadget id="calculator">1 + 19</gadget>
<output>20</output>

<gadget id="calculator">1_500 / 20</gadget>
<output>75</output>

<gadget id="calculator">75 + 75</gadget>
<output>150</output>

<result>150</result>