The highway between the two places is 324 kilometers long. A and B ride motorcycles from two places at the same time. A travels 45 kilometers per hour, and B's speed is A's (4/5). How many hours did the two meet?
两地间的公路长324千米．甲、乙两人骑摩托车分别从两地同时相对开出．甲每小时行45千米，乙的速度是甲的(4/5)．经过多少小时两人相遇？
<gadget id="calculator">4 / 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">324 / 81</gadget>
<output>4</output>

<result>4</result>