A, B, and C start at the same point on a 2790-meter-long circular road at the same time. A and B are going in the same direction, and C and A and B are walking away from each other. A walks 80 meters per minute, and B walks 70 meters per minute. C meets A at a distance of 180 meters from B. How many meters does C walk per minute?
甲、乙、丙三人在长2790米的环形路上的同一地点同时出发，甲、乙同向，丙与甲、乙背向而走，甲每分钟走80米，乙每分钟走70米，丙在距离乙180米处遇见甲．丙每分钟走多少米．
<gadget id="calculator">80 - 70</gadget>
<output>10</output>

<gadget id="calculator">180 / 10</gadget>
<output>18</output>

<gadget id="calculator">2_790 / 18</gadget>
<output>155</output>

<gadget id="calculator">155 - 80</gadget>
<output>75</output>

<result>75</result>