The distance between A and B is 1800 meters. A and B start from A, and C starts from B at the same time and walks towards A and B. It is known that A, B, and C are at speeds per minute. 60 meters, 80 meters and 100 meters, when B and C meet, how many meters is A behind B?
A、B两地相距1800米，甲、乙二人从A地出发，丙同时从B地出发与甲、乙二人相向而行，已知甲、乙、丙三人的速度分别是每分钟60米、80米和100米，当乙和丙相遇时，甲落后于乙几米？
<gadget id="calculator">80 - 60</gadget>
<output>20</output>

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

<gadget id="calculator">1_800 / 180</gadget>
<output>10</output>

<gadget id="calculator">20 * 10</gadget>
<output>200</output>

<result>200</result>