A: B = 2: 3

X: B = 2: 3

Then the speed b = 3/2x =1.5x.

(x+ 1.5x)*3=24

X=3.2 (km/h)

B = 1.5*3.2=4.8 (km/h)

A travels 3.2 kilometers per hour and B travels 4.8 kilometers per hour.