A is two hours ahead of schedule, so it is 2×4=8km.

4X+6X+8=40, that is, the distance traveled by Party A and Party B respectively plus the previous 8km traveled by Party A, ***40km.

X=3.2 hours, with a distance of 20.8 km.

Let the time for two people to meet again be x, and each of them will walk the remaining distance, from point B to point B. The sum of the distances is 40KM, and the sum of the distances to meet back and forth is still 40km, that is, they will walk two 40km.

4X+6X=80，X=8

It will take them eight hours to meet again.

The first meeting point is 20.8 km away from A, and the time for B to arrive at A is 20.8÷6. The remaining time, that is, the distance from A to the point where they met for the second time is 8-20.8÷6, and the final distance to A is 6×(8-20.8÷6)=27.2.

The final score is 27.2km.

Be sure to multiply and divide before adding and subtracting.