A car travels from A to B, and it is planned to take 5 hours to arrive at B, but it actually arrives at B in 4 hours. By what percentage is the actual speed higher than planned? What is the formula
一辆汽车从甲地开往乙地，计划用5小时到达，实际4小时到达乙地．实际速度比计划提高百分之几？算式为多少
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/20) / (1/5)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>