Xiaohong goes to school from home. If she walks 50 meters per minute, she will be late for 3 minutes; if she walks 70 meters per minute, she can arrive at school 1 minute earlier. How far is Xiaohong's home from school?
小红从家里去学校，如果每分钟走50米，就要迟到3分钟；如果每分钟走70米，可以提前1分钟到学校，小红家离学校多少米．
<gadget id="calculator">50 * 3</gadget>
<output>150</output>

<gadget id="calculator">70 * 1</gadget>
<output>70</output>

<gadget id="calculator">150 + 70</gadget>
<output>220</output>

<gadget id="calculator">70 - 50</gadget>
<output>20</output>

<gadget id="calculator">220 / 20</gadget>
<output>11</output>

<gadget id="calculator">11 + 3</gadget>
<output>14</output>

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

<result>700</result>