Teacher Zhang went from school to the county town for a meeting. After he walked at a speed of 50 meters per minute for 2 minutes, he found that he would be 8 minutes late if he walked at this speed, so he speeded up and walked 10 meters more per minute. In the county seat, there are still 5 minutes left before the meeting. Do you know how many meters it is from the school to the county seat?
张老师从学校到县城去开会，他以每分50米的速度走了2分后，发现按这个速度走下去要迟到8分，于是他加快了速度，每分多走了10米，结果到县城时，离开会时间还有5分．你知道学校到县城的路程是多少米．
<gadget id="calculator">2 * 50</gadget>
<output>100</output>

<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">8 * 50</gadget>
<output>400</output>

<gadget id="calculator">8 * 10</gadget>
<output>80</output>

<gadget id="calculator">5 * 50</gadget>
<output>250</output>

<gadget id="calculator">5 * 10</gadget>
<output>50</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">50 - 100</gadget>
<output>-50</output>

<gadget id="calculator">100 + 20 + 400 + 80 + 250 + (-50)</gadget>
<output>800</output>

<gadget id="calculator">1 / 50</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">(1/50) * 50</gadget>
<output>1</output>

<gadget id="calculator">(1/50) * 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) - 1</gadget>
<output>-4/5 = around -0.8</output>

<gadget id="calculator">1 + (-4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">800 / (1/5)</gadget>
<output>4_000</output>

<result>4_000</result>