On the 400 meter circular track, Zhang Qiang runs 320 meters per minute, and Li Na runs 280 meters per minute. Zhang Qiang and Li Na start from the same direction at the same time. When they meet for the first time in t minutes, it is t=______ .

On the 400 meter circular track, Zhang Qiang runs 320 meters per minute, and Li Na runs 280 meters per minute. Zhang Qiang and Li Na start from the same direction at the same time. When they meet for the first time in t minutes, it is t=______ .

Let two people meet for the first time in t minutes. From the meaning of the question, 320x-280x = 400, the solution is: x = 10