Analysis Because two people are even, we can directly draw a conclusion with the distance ratio of Party A and Party B twice ... Specifically:

A The distance for the first trip is: halfway through the journey. 150.

The second trip of A is: less than half of the journey 150+ half of the journey +450, that is, the journey is more than 300.

It is not difficult to see that the distance ratio of A twice is 1: 2.

B The second distance is: 150+450=600 meters.

Then the corresponding distance of B's first trip is 300 meters.

The distance of your first trip is less than half of the journey 150.

So half of the whole journey is: 300+ 150=450.

The whole journey is: 450× 2 = 900m m.

Solution: Let the whole journey be s meters.

( 1/2s- 150)/( 150+450)=( 1/2s+ 150)/( 1/2s- 150+ 1/2s+450)

( 1/2s- 150)/600 = 1/2

1/2s- 150=300

s=900

A: The distance between a:AB and Beijing is 900 meters.