The distance between the east and west villages is 4200 meters. A starts from the east village, and B and C start from the west village at the same time. 100 meters per minute, how many meters does C walk per minute?
东西两村相距4200米，甲从东村、乙和丙从西村同时出发，甲与乙、丙相向而行，甲与乙相遇后1分钟甲与丙相遇，甲每分钟走110米，乙每分钟走100米，丙每分钟走多少米．
<gadget id="calculator">100 + 110</gadget>
<output>210</output>

<gadget id="calculator">4_200 / 210</gadget>
<output>20</output>

<gadget id="calculator">20 + 1</gadget>
<output>21</output>

<gadget id="calculator">4_200 / 21</gadget>
<output>200</output>

<gadget id="calculator">200 - 110</gadget>
<output>90</output>

<result>90</result>