Answer:
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The time they arrive at the destination is 9:24 am the next day
How to determine the time they arrive at the destination.
From the question, we have the following parameters that can be used in our computation:
Time = 4 pm
Distance = 64 km
Start by calculating time taken for the father to ride the horse and son to walk the first 32 km:
Time = Distance / (Difference between rates of father and son)
Time = 32 km / (8 km/h - 3 km/h)
Time = 32 km / 5 km/h
Time = 6.4 hours
Calculate time taken for the son to ride the horse and father to walk the remaining 32 km:
Time = Distance / (Difference in Speed)
Time = 32 km / (8 km/h - 4 km/h)
Time = 32 km / 4 km/h
Time = 8 hours
So, we have
Total time = 6.4 hours + 8 hours + 3 hours break + 4 pm
Evaluate
Total time = 9:24 am the next day.