Answer:
5 km/h
Explanation:
Let x km/h be Ed's rate in the evening, then x+1 km/h is his rate in the morning. It takes him
hours in the morning to pass 12 km;
hours in the evening to pass 12 km.
In total, it takes him 5 hours 24 minutes (
hours), then

Solve this equation:

Ed's rate cannot be negative, thus x=4 km/h. His morning rate is x+1=5 km/h.