A and B are traveling toward each other from two places 150 kilometers apart. A travels 30 kilometers per hour, and B travels 20 kilometers per hour. How long did it take to meet each other?
甲、乙两人分别从相距150千米的两地相向而行，甲每小时行驶30千米，乙每小时行驶20干米，问经过多长时间相遇？
<gadget id="calculator">30 + 20</gadget>
<output>50</output>

<gadget id="calculator">150 / 50</gadget>
<output>3</output>

<result>3</result>