The distance between the two places is 450 kilometers. Cars A and B drive from the two places at the same time. It is known that car A travels 50 kilometers per hour, and the speed of car B is 4/5 of that of car A. How long does it take for cars A and B to meet?
两地相距450千米，甲乙两车同时从两地相对开出，已知甲车每小时行50千米，乙车的速度是甲车的(4/5)，甲乙两车几小时相遇？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">50 * (4/5)</gadget>
<output>40</output>

<gadget id="calculator">50 + 40</gadget>
<output>90</output>

<gadget id="calculator">450 / 90</gadget>
<output>5</output>

<result>5</result>