Master Wang processed a batch of parts, 60% of the parts were processed in 3 days, and 150 parts were processed in the fourth day. At this time, there were still 1/5 of the total number that had not been processed. How many parts are there in this batch?
王师傅加工一批零件，3天正好加工了这批零件的60%，第四天加工了150个，这时，还有总数的(1/5)没有加工．这批零件共有多少个？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (3/5) - (1/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">150 / (1/5)</gadget>
<output>750</output>

<result>750</result>