A truck travels from A to B at 40 kilometers per hour, and a passenger car travels from B to A at 45 kilometers per hour. When they meet, the passenger car travels 20 kilometers longer than the truck. How many miles is the distance between B and B?
一辆货车从甲地开往乙地，每小时行40千米，一辆客车从乙地开往甲地，每小时行45千米，相遇时，客车比货车多行20千米，甲、乙两地相距多少千米．
<gadget id="calculator">40 + 45</gadget>
<output>85</output>

<gadget id="calculator">45 - 40</gadget>
<output>5</output>

<gadget id="calculator">20 / 5</gadget>
<output>4</output>

<gadget id="calculator">85 * 4</gadget>
<output>340</output>

<result>340</result>