The production of garlands for the 90th anniversary of the founding of the Communist Party of China was originally planned to be 100 per hour and completed in 6 hours. The actual production was 20 more per hour than the original plan. How many hours was the actual completion earlier than the original plan?
迎建党90周年文艺汇演制作花环，原计划每小时制作100个，6小时完成，实际每小时比原计划做多20个，实际比原计划提前了多少小时完成？
<gadget id="calculator">100 + 20</gadget>
<output>120</output>

<gadget id="calculator">6 / 120</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">100 * (1/20)</gadget>
<output>5</output>

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

<result>1</result>