From City A to City B, it takes 3 hours for the express train and 5 hours for the slow train. The speed of the slow train is 45 km/h. How much more miles per hour does the express train travel than the slow train?
从甲城到乙城，快车3小时到达，慢车5小时才能到达．慢车的速度是45千米/时．快车每小时比慢车多行多少千米？
<gadget id="calculator">5 / 3</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">45 * (5/3)</gadget>
<output>75</output>

<gadget id="calculator">75 - 45</gadget>
<output>30</output>

<result>30</result>