Let Chen Hua's speed be VB, Zhang Lin's speed be the distance between VA, AB and S, the time between the third meeting is T, the distance to B is DB, and A is D A..

When they first met, their total distance was s:

1(VB+VA)=S

When we met for the second time, Chen walked more than Zhang. Student:

1.5(VB-VA)=S

When we met for the third time, because Chen was faster than Zhang, Chen had returned to point B and started again, but Zhang had not arrived at point B, so Chen left 2S+B and Zhang left A, because A+B=S:

(VB+VA)T=3S

DB=VB*T-2S

DA=3S-VB*T

The solution is VB=5S/6 and VA=S/6.

DB=DA=S/2

The ratio is 1: 1.