The length of the railway between A and B is 550 kilometers. A freight train leaves from A, and a passenger train departs from B at the same time. The two trains travel towards each other. After 3 hours, the distance is still 43 kilometers. The freight train travels 79 kilometers per hour. How many kilometers does the bus travel per hour?
甲乙两地的铁路长550千米，一列货车从甲开出，同时有一列客车从乙地开出，两车相向而行，经过3小时还相距43千米，货车每小时行79千米，客车每小时行多少千米？
<gadget id="calculator">550 - 43</gadget>
<output>507</output>

<gadget id="calculator">507 / 3</gadget>
<output>169</output>

<gadget id="calculator">169 - 79</gadget>
<output>90</output>

<result>90</result>