Master Zhang processed a batch of machine parts, 50 on the first day, and 25% of the parts on the second day. At this time, the ratio of processed parts to unprocessed parts was 1:2. How many parts are there in total?
张师傅加工一批机器零件，第一天加工了50个，第二天又加工了这批零件的25%，这时已加工的个数与未加工个数的比是1：2，这批零件共有多少个？
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/3) - (1/4)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">50 / (1/12)</gadget>
<output>600</output>

<result>600</result>