After the opening of the Ningbo-Taizhou-Wenzhou Railway EMU, it will take 2 hours to travel from Wenzhou to Hangzhou at a speed of 250 kilometers per hour. If it takes 2.5 hours to arrive, how many kilometers per hour should the speed be? (Solve with ratio)
甬台温铁路动车组开通后，以每小时250千米的速度计算，从温州到杭州需要2小时．若需2.5小时到达，那么速度应是每小时多少千米？(用比例解)
<gadget id="calculator">250 * 2</gadget>
<output>500</output>

<gadget id="calculator">500 / 2.5</gadget>
<output>200</output>

<result>200</result>