Two cars A and B drive towards each other at the same time from two places 272 kilometers apart. After 3 hours, the two cars have not met, and the distance between the two cars is 17 kilometers. If car A travels 45 kilometers per hour, how many kilometers per hour does car B travel?
甲乙两辆汽车同时从相距272千米的两地相向开出，3小时后两车还没相遇，此时两车相距17千米．如果甲车每小时行45千米，乙车每小时行多少千米？
<gadget id="calculator">272 - 17</gadget>
<output>255</output>

<gadget id="calculator">255 / 3</gadget>
<output>85</output>

<gadget id="calculator">85 - 45</gadget>
<output>40</output>

<result>40</result>