The distance between A and B is 405 kilometers. A truck and a passenger car start from the two places at the same time and drive toward each other. It is known that the passenger car travels 45 kilometers per hour, and the speed of the truck is (1/5) slower than that of the passenger car. How long will it take for the two cars to meet?
甲、乙两地相距405千米，一辆货车和一辆客车分别从两地同时出发，相向而行．已知客车每时行驶45千米，货车的速度比客车慢(1/5)．经过多长时间两车可以相遇？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">45 * (4/5)</gadget>
<output>36</output>

<gadget id="calculator">45 + 36</gadget>
<output>81</output>

<gadget id="calculator">405 / 81</gadget>
<output>5</output>

<result>5</result>