The distance between A and B is 3,400 meters. Li Hua walks 40 minutes to go and 5 minutes to return. How many meters does Li Hua go back and forth per branch?
甲乙两地相距3400米，李华同学去时走40分，回来时多走5分，李华来回平均每分行多少米？
<gadget id="calculator">40 + 5 + 40</gadget>
<output>85</output>

<gadget id="calculator">2 / 85</gadget>
<output>2/85 = around 0.023529</output>

<gadget id="calculator">3_400 * (2/85)</gadget>
<output>80</output>

<result>80</result>