Xiao Ding Ding and Xiao Qiao run around the circular playground. They start from the same place and run in opposite directions. Xiaoqiao runs 3 meters per second, and Xiao Dingding runs 4 meters per second. After 1 minute and 10 seconds, the two meet. How long is the school runway?
小丁丁和小巧绕着环形操场跑步，两人从同一地点出发，沿着相反方向跑步．小巧每秒跑3米，小丁丁每秒跑4米，1分10秒后两人相遇，学校跑道有多长？
<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">7 * 70</gadget>
<output>490</output>

<result>490</result>