Students in class 6 and 1 planted a batch of trees and planned to complete it in 5 hours. The actual work efficiency increased by 25%, so how many hours can the task be completed in advance.
六1班同学植一批树，计划5小时完成，实际工作效率提高了25%，这样可以提前多少小时完成任务．
<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">5 / (5/4)</gadget>
<output>4</output>

<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<result>1</result>