Xiaohua walks 60 meters per minute when going to school, and 80 meters per minute when leaving school. In this way, it took her 21 minutes to walk to and from school. How far is the distance from her home to school?
小华上学时每分钟走60米，放学时每分钟走80米，这样她上学、放学走路共用去了21分钟，她家到学校的路程有多远？
<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">1 / 80</gadget>
<output>1/80 = around 0.0125</output>

<gadget id="calculator">(1/60) + (1/80)</gadget>
<output>7/240 = around 0.029167</output>

<gadget id="calculator">21 / (7/240)</gadget>
<output>720</output>

<result>720</result>