Uncle Wang produces a batch of parts, the ratio of the finished parts to the unmade parts is 2:5, and he completes the remaining 50 in 2 hours. How many parts are there in total?
王叔叔生产一批零件，已做的零件与未做的零件比为2：5，剩下的50个他2小时就完成了，这批零件共有多少个．
<gadget id="calculator">50 / 5</gadget>
<output>10</output>

<gadget id="calculator">2 + 5</gadget>
<output>7</output>

<gadget id="calculator">10 * 7</gadget>
<output>70</output>

<result>70</result>