11. On an elliptical track with a perimeter of 400 meters, two people, A and B, start cycling from two points 300 meters apart and head towards each other along the track. After meeting, they continue to move forward. It is known that A's cycling speed is 4 meters/second, and B's cycling speed is 6 meters/second. When they meet for the 6th time, the two have cycled for at least (
) seconds
210
【Answer】Since it is "at least", the first meeting took 10 seconds. After that, every time they meet, the two together have walked one circumference, so it must be 40 seconds; therefore, meeting 6 times took at least $5 \times 40+10=210$ seconds