A truck and a passenger car leave from places A and B at the same time. After a while, the two cars meet. At this time, the bus travels (1/2) more than 40 kilometers of the whole journey, and the truck travels less than half of the whole journey (1/10). How many miles is the distance between A and B?
一辆货车和一辆客车同时从甲、乙两地相对开出，一段时间后，两车相遇．此时，客车行了全程的(1/2)多40千米，货车行了全程的一半少(1/10)．甲、乙两地之间相距多少千米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/2) - (1/10)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5) - (1/2)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">40 / (1/10)</gadget>
<output>400</output>

<result>400</result>