Processing a batch of parts, A and B work together for 6 hours to complete, if B alone takes 15 hours to complete the task, when A and B cooperate to complete the task, A gives B 60 parts, the number of parts processed by the two is exactly equal ． How many parts are there in this batch?
加工一批零件，甲、乙两人合做6小时完成，如果由乙单独加工要15小时完成，当甲、乙合作完成任务时，甲给乙60个零件，两人加工的零件数正好相等．这批零件有多少个？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/6) - (1/15)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) * 6</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(1/15) * 6</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2 / (1/5)</gadget>
<output>10</output>

<gadget id="calculator">60 * 10</gadget>
<output>600</output>

<result>600</result>