The distance between A and B is 300 kilometers. If a car travels from A to B, if the speed of the car is increased by 20%, it can arrive 1 hour earlier. arrive in hours. How many kilometers is a?
甲、乙相距300千米，一辆汽车从甲地到乙地，如果车速提高20%，可提前1小时到达，如果原速行驶a千米后，再将速度提高25%，也可提前1小时到达．a是多少千米？
<gadget id="calculator">300 / 50</gadget>
<output>6</output>

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

<gadget id="calculator">3_125 * 5</gadget>
<output>15_625</output>

<gadget id="calculator">15_625 - 15_000</gadget>
<output>625</output>

<gadget id="calculator">625 / 12.5</gadget>
<output>50</output>

<result>50</result>