bus departs from Zhangzhuang, if it travels an average of 70 kilometers per hour, it can reach Lizhuang in 5 hours. The actual average travel distance is 20 kilometers per hour, and how many hours does it take to reach Lizhuang?
一辆大巴车从张庄出发，如果平均每小时行70千米，5小时能到李庄．实际平均每小时少行20千米，实际几小时到达李庄？
<gadget id="calculator">70 * 5</gadget>
<output>350</output>

<gadget id="calculator">70 - 20</gadget>
<output>50</output>

<gadget id="calculator">350 / 50</gadget>
<output>7</output>

<result>7</result>