Two trains start opposite each other from two places 530 kilometers apart. Car A travels 52 kilometers per hour. Train B starts after 2 hours after A train leaves. The two trains meet each other after 4 hours. How many kilometers per hour?
两列火车从相距530千米的两地相对开出，甲车每小时行52千米，甲车开出2小时后乙车才出发，乙车开出4小时后两车相遇，乙车每小时行多少千米？
<gadget id="calculator">52 * 2</gadget>
<output>104</output>

<gadget id="calculator">530 - 104</gadget>
<output>426</output>

<gadget id="calculator">426 / 4</gadget>
<output>213/2 = around 106.5</output>

<gadget id="calculator">(213/2) - 52</gadget>
<output>109/2 = around 54.5</output>

<result>109/2 = around 54.5</result>