The speed of the high-speed rail can reach 280km/hour, which is 30km more than twice that of the express train. What is the speed of the express train in km/h?
高铁速度能达到280km/时，比物快火车的2倍还多30km．特快火车速度是多少千米/时？
<gadget id="calculator">280 - 30</gadget>
<output>250</output>

<gadget id="calculator">250 / 2</gadget>
<output>125</output>

<result>125</result>