Master Wang planned to process a batch of parts in 2 hours. When there were 160 parts left, the machine broke down, and the efficiency was reduced by 1/5. As a result, the task was completed 20 minutes later than the original plan. How many parts are there in this batch?
王师傅计划用2小时加工一批零件，当还剩160个零件时，机器出现故障，效率比原来降低1/5，结果比原计划推迟20分钟完成任务，这批零件有多少个？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / (4/5)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(5/4) - 1</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/3) / (1/4)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">160 / (4/3)</gadget>
<output>120</output>

<gadget id="calculator">120 * 2</gadget>
<output>240</output>

<result>240</result>