A car drives from place A to place B, travels 75 kilometers per hour when going there, and travels 50 kilometers per hour when returning. It takes 10 hours to go back and forth. What is the distance in kilometers between places A and B?
汽车从甲地开往乙地，去时每小时行75千米，返回时每小时行50千米，来回一共用了10小时，甲，乙两地的距离是多少千米．
<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">10 * (2/5)</gadget>
<output>4</output>

<gadget id="calculator">75 * 4</gadget>
<output>300</output>

<result>300</result>