Two trains, A and B, depart opposite from each other and meet at a distance of 45 kilometers from the midpoint after 6 hours. The slow train travels 50 kilometers per hour. How many kilometers per hour does the express train travel?
甲、乙两列火车从两地相对开出，6小时后在距离中点45千米处相遇，慢车每小时行50千米，快车每小时行多少千米？
<gadget id="calculator">50 * 6</gadget>
<output>300</output>

<gadget id="calculator">45 * 2</gadget>
<output>90</output>

<gadget id="calculator">300 + 90</gadget>
<output>390</output>

<gadget id="calculator">390 / 6</gadget>
<output>65</output>

<result>65</result>