The distance between A and B is 810 kilometers. Two trains travel towards each other from the two places at the same time and meet each other after 6 hours. The speed of A train is 75 kilometers per hour. What is the speed of B train?
甲、乙两地相距810千米，两列火车分别从两地同时相向而行6小时后相遇，甲车的速度是每小时75千米，乙车的速度是多少？
<gadget id="calculator">810 / 6</gadget>
<output>135</output>

<gadget id="calculator">135 - 75</gadget>
<output>60</output>

<result>60</result>