A truck travels from place A to place B at a speed of 75km per hour. After staying for 1.5 hours, it returns at the same speed. The round trip takes 3.9 hours. How many kilometers are there between places A and B?
一辆货车以每小时75km的速度从甲地行驶到乙地，停留1.5小时后以同样的速度返回，往返共用3.9小时，甲、乙两地相距多少千米？
<gadget id="calculator">3.9 - 1.5</gadget>
<output>2.4</output>

<gadget id="calculator">75 / 2</gadget>
<output>75/2 = around 37.5</output>

<gadget id="calculator">2.4 * (75/2)</gadget>
<output>90</output>

<result>90</result>