After the speed increase of trains in my country, the average speed of trains on a certain railway line is 200 kilometers per hour, which is 40 kilometers per hour faster than before the speed increase. How many percent has the train speed increased?
我国火车提速后，某铁路干线上火车速度是平均每小时200千米，比提速前每小时快40千米，火车速度提高了百分之几？
<gadget id="calculator">200 - 40</gadget>
<output>160</output>

<gadget id="calculator">40 / 160</gadget>
<output>1/4 = around 0.25</output>

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