Two people, A and B, walk towards each other from A and B at the same time. A walks 100 meters per minute, and the speed ratio to B is 5:4. After 5 minutes, the two walk exactly the whole distance (1/4). What is the distance between A and B?
甲、乙两个人同时从A、B两地相向而行，甲每分钟走100米，与乙的速度比是5：4，5分钟后，两人正好行了全程的(1/4)，A、B两地相距多少米？
<gadget id="calculator">100 / 5</gadget>
<output>20</output>

<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<gadget id="calculator">80 + 100</gadget>
<output>180</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">5 / (1/4)</gadget>
<output>20</output>

<gadget id="calculator">180 * 20</gadget>
<output>3_600</output>

<result>3_600</result>