Obviously there are 300 meters from home to school, and he walks an average of 50 meters per minute, how many minutes does it take to go back and forth.
明明从家到学校有300米，他平均每分钟行50米，往返一次需要多少分钟．
<gadget id="calculator">2 / 50</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">300 * (1/25)</gadget>
<output>12</output>

<result>12</result>