Time for Dagang to walk 100 meters: 100/2.6=500/ 13 seconds,
The time of floret walking 100 m:100/2.2 = 500/11sec,
30 minutes, Dagang walk: 30*60/500/ 13=46.4.
Xiaohong Zuo: 30 * 60/500/11= 39.6.
Because the common multiples of 500/13,500/1are not within 30*60= 1800 seconds, I have met Xiaohong once in every whole journey of Dagang, with 46 times.