The road construction is 1500 meters in 30 days, but the actual number of meters of road construction per day is 1.2 times of the original plan. How many days can it be completed in advance?
筑路对计划30天修路1500米，实际每天修路的米数是原计划每天修的1.2倍，这样可提前几天完成？
<gadget id="calculator">1_500 / 30</gadget>
<output>50</output>

<gadget id="calculator">50 * 1.2</gadget>
<output>60</output>

<gadget id="calculator">1_500 / 60</gadget>
<output>25</output>

<gadget id="calculator">30 - 25</gadget>
<output>5</output>

<result>5</result>