The botanical garden plans to plant 80 trees every day, which can be completed in 15 days. The actual number is 25% higher than the original plan every day. How many days ahead of schedule can the task be completed?
植物园计划每天种树80棵，15天可以种完，实际每天比原计划多种25%，提前几天完成任务？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">80 * (5/4)</gadget>
<output>100</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">80 * (3/20)</gadget>
<output>12</output>

<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<result>3</result>