The key to doing this kind of problem is to understand the relationship between cars and people, so it is not difficult.

In fact, the time spent is the sum of all the time spent by another car that is not broken after one car breaks down.

The money is divided into three parts. 1 >; /kloc-the distance of 0/5 km needs 15/60 hours.

2> Time, total distance/speed from the time when the fans leave and the car returns.

When the first group of fans were taken to the hospital by bus, the walking distance of fans was 5X 1/4 (speed x time).

So the total distance is 15-5x 1/4 (the distance from the focus after the fan fails when the first car reaches the finish line).

Because they are going in the opposite direction, it takes 13.75/(60+5).

3> The third part is the same as the second part. I can draw a picture by myself. The distance between the car and the fans is the same as the distance between the car and the fans. So the second part is the same as the third part, which is 13.75/(60+5).

So the delivery time should be

1/4+13.75/(60+5)+13.75/(60+5) = 40.38 minutes.

So that you can arrive within the specified time. ........