The school organized students to climb the Wushan Mountain. Li Ziwei walked up the mountain at 40 meters per minute. It took him 3 hours and 20 minutes to climb from the foot of the mountain to the top. After resting for 1 hour, he goes down the mountain by the same route, walking 50 meters per minute, how long does it take to walk from the top of the mountain to the foot of the mountain?
学校组织同学爬观雾山，李自伟上山每分钟走40米，用了3小时20分从山脚爬到山顶．休息1小时后，他按原路下山，每分钟走50米，从山顶走到山脚需要多少时间？
<gadget id="calculator">200 / 50</gadget>
<output>4</output>

<gadget id="calculator">40 * 4</gadget>
<output>160</output>

<result>160</result>