When the remaining distance of B is four times that of A, the distance ratio between A and B is still 3; 2

If A goes 3-2= 1, it leaves 4- 1=3 (taking the remaining distance of A as 1), which proves that 1=3.

Then A walked three times, which means he walked 3x3=9 segments, leaving 1 segment. A * * * with 10 segments.

A walked 9/ 10, and it took 4x9/ 10= 18/5 hours.

Comprehensive formula

6; 4=3; 24x {(4-1) ÷ (3-2) x3} ÷ {(4-1) ÷ (3-2) x3+1} =18/5 hours.