Master Wang processes a batch of parts. The original plan is to process 30 parts per hour, which can be completed in 6 hours. The actual processing time is 20% more than the original plan. How many hours earlier than the original plan?
王师傅加工一批零件，原计划每小时加工30个，6小时可以完成，实际每小时比原来计划多加工20%，实际加工这批零件比原计划提前几小时？
<gadget id="calculator">30 * 6</gadget>
<output>180</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">30 * (6/5)</gadget>
<output>36</output>

<gadget id="calculator">180 / 36</gadget>
<output>5</output>

<gadget id="calculator">6 - 5</gadget>
<output>1</output>

<result>1</result>