Kobayashi goes from home to school at 7:30 in the morning, walking 50 meters per minute. As soon as I arrived at the school gate, I found that I didn't bring my math books, so I immediately returned along the original road, walking 70 meters per minute. It was exactly 7:54 when I got home. How far is Xiaolin's house from the school?
小林早晨7：30从家去学校，每分钟走50米．刚到学校门口发现数学书没有带，立即沿原路返回，每分钟走70米．到家正好是7：54．小林家离学校多少米？
<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">24 * (7/12)</gadget>
<output>14</output>

<gadget id="calculator">50 * 14</gadget>
<output>700</output>

<result>700</result>