Reward score: 25- 19 days 13 hours before the problem ends.

One day, grandpa and Xiaogang are going to play in the riverside park from home. After grandpa set off, 10 minutes later, Xiao just rode his bicycle eye and chased after him on the same route. On the way, the bicycle tire was punctured by glass fragments, and someone went to mend it. As shown in the figure, the average speed v of Grandpa and Xiaogang in each time period changes with time t.. According to the information provided by the picture, answer:

1. How far are Grandpa and Xiaogang's homes from the park?

2. In the process of going to the park, how many minutes did the two meet after Grandpa left?

3. When grandpa arrived at the park, how far was Xiaogang from the park?

Xiaogang wants to arrive at the park with his grandfather. How much will his average speed increase after the bicycle is repaired?