A and B start from two places A and B which are 1200 meters apart at the same time, and walk in the same direction. B is in front and A is behind. When they walk for 10 minutes, the distance between the two people is equal to point B. When they walk for 100 minutes, A catches up with B. How many meters does B walk per minute?
甲、乙两人同时分别从相距1200米的A、B两地步行出发，同向而行．乙在前，甲在后．当他们步行10分钟后，两人离B地的距离相等，当他们步行100分钟，甲追上乙．乙每分钟步行多少米．
<gadget id="calculator">1_200 / 100</gadget>
<output>12</output>

<gadget id="calculator">12 * 10</gadget>
<output>120</output>

<gadget id="calculator">1_200 - 120</gadget>
<output>1_080</output>

<gadget id="calculator">10 + 10</gadget>
<output>20</output>

<gadget id="calculator">1_080 / 20</gadget>
<output>54</output>

<result>54</result>