A and B walk across a bridge. A took 20 minutes and B took 25 minutes. It is known that A walks 20 meters more than B per minute. How long is the bridge in meters?
甲、乙两人步行通过一座大桥．甲用了20分钟，乙用了25分钟．已知甲每分钟比乙多走20米．这座桥全长多少米？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 25</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">(1/20) - (1/25)</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">20 / (1/100)</gadget>
<output>2_000</output>

<result>2_000</result>