As shown in the picture, there is a 300 meter small track in the 400 meter track of the school playground. The distance between the large track and the small track is 200 meters. A runs counter clockwise along the large track at the speed of 6 meters per second, and B runs clockwise along the small track at the speed of 4 meters per second. The two start from the intersection a of the two runways at the same time. When they meet on the runway for the second time, how many meters did a run?

As shown in the picture, there is a 300 meter small track in the 400 meter track of the school playground. The distance between the large track and the small track is 200 meters. A runs counter clockwise along the large track at the speed of 6 meters per second, and B runs clockwise along the small track at the speed of 4 meters per second. The two start from the intersection a of the two runways at the same time. When they meet on the runway for the second time, how many meters did a run?

The time of the first meeting is 400 (6 + 4) = 40 (seconds). The distance of the first meeting a is: 40 × 6 = 240 (meters). The distance of the first meeting B is: 40 × 4 = 160 (meters). The time of B returning to the starting point a: (300-160) × 4 = 140 (seconds). The distance of the first meeting a is: 6 × 35 = 210 (...)