The express train and the local train depart from two cities 360 kilometers apart at the same time, and they meet on the way after 4 hours. It is known that the speed ratio of the express train and the local train is 5:4. How many kilometers does the slow train travel per hour?
快车和慢车同时从相距360千米的两城相对开出，4小时后在途中相遇，已知快车和慢车的速度比是5：4，慢车每小时行多少千米？
<gadget id="calculator">360 / 4</gadget>
<output>90</output>

<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">90 * (4/9)</gadget>
<output>40</output>

<result>40</result>